i am running my own Mailserver, which works fine, but not for some targets. Basically I can send mails to everybody, except to *@gmx.net and *@web.de, If I do that, it takes about an week and then I get a Undelivered Mail Returned to Sender mail. Within that I find that error:  Diagnostic-Code: smtp; 554-gmx.net (mxgmx114) Nemesis ESMTP Service not available 554-No SMTP service 554-Bad DNS PTR resource record.   I have been googling for that and found some explanation, but I still do not know what to put where in the DNS record.  Right now I have that in the TXT part of the DNS  v=spf1 a mx ptr -all   But it is not working. How can I fix that?
123705
Currently, my server is running Ubuntu Server. I had the domain "rosresurs.msk.ru". A bit later I've bought a new domain called "rosresurs.net". But when I ran dig command, I saw, that old domain is linked to my server's IP. I've looked to both DNS zones. In .msk.ru there is no server's IP. Domain .net has PTR record. Also, I asked for help my domain hosting. Thay said, that it is out fault. I've searched the whole system for rosresurs.msk.ru and its IP address. I've deleted all that entries. But after 2 days nothing changed.
88517
This is a  about DNS (Domain Name Service).   If my understanding of the DNS system is correct, the .com registry holds a table that maps domains (www.example.com) to DNS servers.   What is the advantage? Why not map directly to an IP address? If the only record that needs to change when I am configuring a DNS server to point to a different IP address, is located at the DNS server, why isn't the process instant? If the only reason for the delay are DNS caches, is it possible to bypass them, so I can see what is happening in real time?
122492
SQL Sever 2016 with the latest updates. Running on WS2012R2. Following error message is received:     The mail could not be sent to the recipients because of the mail server failure. (Sending Mail using Account 5 (2017-04-14T21:34:10). Exception Message: Cannot send mails to mail server. (The operation has timed out.).  )   I have tried several ways of setting up Database Mail, a mixture of precreated scripts and following the interface in SSMS.   I have also tried two different mail server credentials (Google and a Web Hosting Company), and both fail with the same error.  The Web Hosting Credentials are used on a PHP Script on another Server which works perfectly fine.  What should I check to get this working?
58087
I started a new service and we need to send emails to our customers (new account confirms, etc).   My server is known as prod01.bidrodeo.com and resolves to 97.107.134.38 .  For reverse DNS, 97.107.134.38 resolves to prod01.bidrodeo.com . However, all our email addresses are in the form of user@bidrodeo.com. Should I make the reverse DNS point to bidrodeo.com instead?   My emails are getting delayed or rejected by certain systems and i am not sure if my reverse DNS is not set up correctly.
14567
I just got this error message for the first time (I was getting this as the response to any request on the SE network for about the last five minutes, until now):     We're sorry...      There are an unusual number of requests coming from this IP address.   To protect our users, we can't process any more requests from this IP   address right now. We'll restore access as quickly as possible, so try   again soon. If you believe you have reached this page in error,   contact us.   As far as I know, I was not spamming SE or participating in DOS attack, and I find it unlikely that any of my office coworkers who share my IP address were doing so either.  Granted, I was pressing F5 a lot. But I've always pressed F5 a lot on SE, and have never gotten this message before. So my question is: Is it possible to get this error message simply by refreshing too much or too often? Or is that message reserved for a truly massive number of requests that are unlikely to be caused by one person refreshing a lot? (In the former case, I can't explain why I've never gotten it before; in the latter case, I can't explain why I just got it now).
16611
I have heard that most spam filters use a reverse DNS lookup on the originating IP address of the sending SMTP server (or something like that) as part of the verification process.  I want to make sure my emails will pass this check.  How exactly can I verify that my emails are OK?  In researching it, I've noticed that if I look at the header of a valid email message coming from Gmail, I will see something like this:  Received: from mail-pz0-f185.google.com (mail-pz0-f185.google.com [209.85.222.185])         by mx.google.com with ESMTP id 10si2346996pxi.164.2009.07.22.22.26.19;         Wed, 22 Jul 2009 22:26:19 -0700 (PDT)   When I do an nslookup on 209.85.222.18, it responds with mail-pz0-f185.google.com, which is what I would expect.  If it responded with a different domain, then I assume that would indicate a problem and it would fail the check.  Is this what the reverse DNS lookup is all about or am I barking up the wrong tree?
90407
I have a server which uses Postfix as the mail system. The issue I am having is I am not able to send or recieve email. If I send an email I get an instant reply from the server which says:  Subject:    test Sent:   16/05/2011 19:08  The following recipient(s) could not be reached:  'myemail@mydomain.com' on 16/05/2011 19:08 452 4.3.1 Insufficient system storage   I have check the following:  Disk space, there are gigabytes of free space on all partitions. Mailbox quotas, there are no quota,s set on any mailbox.  I cleared all the mail logs and rebooted the server but I still cannot send email. does anyone have any pointers for me to look at next.  I have looked at the main.cf file and here are the results:  virtual_mailbox_domains = $virtual_mailbox_maps, hash:/var/spool/postfix/plesk/virtual_domains virtual_alias_maps = $virtual_maps, hash:/var/spool/postfix/plesk/virtual virtual_mailbox_maps = hash:/var/spool/postfix/plesk/vmailbox transport_maps = hash:/var/spool/postfix/plesk/transport smtpd_tls_cert_file = /etc/postfix/postfix_default.pem smtpd_tls_key_file = $smtpd_tls_cert_file smtpd_tls_security_level = may smtpd_use_tls = yes smtp_tls_security_level = may smtp_use_tls = no smtpd_sender_restrictions = check_sender_access hash:/var/spool/postfix/plesk/blacklists, permit_sasl_authenticated, check_client_access pcre:/var/spool/postfix/plesk/non_auth.re smtp_send_xforward_command = yes smtpd_authorized_xforward_hosts = 127.0.0.0/8 smtpd_sasl_auth_enable = yes smtpd_recipient_restrictions = permit_mynetworks, check_client_access pcre:/var/spool/postfix/plesk/no_relay.re, permit_sasl_authenticated, reject_unauth_destination virtual_mailbox_base = /var/qmail/mailnames virtual_uid_maps = static:110 virtual_gid_maps = static:31 virtual_transport = plesk_virtual plesk_virtual_destination_recipient_limit = 1 smtpd_client_restrictions =  myhostname = mydomain.com message_size_limit = 2048000000
123595
I have a following setup:   linux box with postfix configured to be responsible for example.com domain domain's MX servers are configured so that mail sent to example.com is sent to google mail servers several user accounts on linux machine exist (same machine also hosts example.com site)   When someone from the outside attempts to send mail to address ending with @example.com, it gets routed to google mail (and there handled appropriately).  When linux machine tries to send mail to outside world, mail is delivered correctly, as reverse dns and spf records are configured correctly, so linux machine is valid mail sender for example.com domain (along with google mail servers).  However, here's the problem. When php application (hosted at linux box) tries to send mail to someuser@example.com (and someuser doesn't exist on linux box), it fails, since it doesn't even consult google mail servers, but postfix smtp locally concludes that "someuser" is unknown.  So, the question is: how do I tell postfix to relay mails sent to @example.com domain to google mail servers (so, to servers specified in MX records), IF and only if a mailbox is not found locally.
120729
I've been trying to configure email to forward to Gmail, using Postfix to relay email to smtp.gmail.com. However, I'm failing to get it to authenticate with smtp.gmail.com, which is a rather vital prerequisite to getting anything working…  The mail logs show only:  Oct 29 15:50:14 gsnedders-1 postfix/master[6596]: daemon started -- version 2.7.1, configuration /etc/postfix Oct 29 15:50:19 gsnedders-1 postfix/pickup[6598]: EBA1F78750: uid=1000 from=&lt;gsnedders&gt; Oct 29 15:50:19 gsnedders-1 postfix/cleanup[6603]: EBA1F78750: message-id=&lt;20111029145019.EBA1F78750@mail.gsnedders.com&gt; Oct 29 15:50:19 gsnedders-1 postfix/qmgr[6599]: EBA1F78750: from=&lt;gsnedders@gsnedders.com&gt;, size=324, nrcpt=1 (queue active) Oct 29 15:50:19 gsnedders-1 postfix/cleanup[6603]: F2D557874F: message-id=&lt;20111029145019.EBA1F78750@mail.gsnedders.com&gt; Oct 29 15:50:19 gsnedders-1 postfix/local[6605]: EBA1F78750: to=&lt;me@gsnedders.com&gt;, orig_to=&lt;me&gt;, relay=local, delay=0.04, delays=0.03/0.02/0/0, dsn=2.0.0, status=sent (forwarded as F2D557874F) Oct 29 15:50:19 gsnedders-1 postfix/qmgr[6599]: F2D557874F: from=&lt;gsnedders@gsnedders.com&gt;, size=454, nrcpt=1 (queue active) Oct 29 15:50:19 gsnedders-1 postfix/qmgr[6599]: EBA1F78750: removed Oct 29 15:50:20 gsnedders-1 postfix/smtp[6606]: warning: SASL authentication failure: No worthy mechs found Oct 29 15:50:20 gsnedders-1 postfix/smtp[6606]: F2D557874F: SASL authentication failed; cannot authenticate to server smtp.gmail.com[74.125.157.108]: no mechanism available   And the postfix config is:  relayhost = [smtp.gmail.com]:587  smtp_use_tls = yes smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/sasl/passwd smtp_sasl_security_options = noanonymous  smtp_tls_eccert_file = smtp_tls_eckey_file = smtp_tls_security_level = may smtp_tls_CAfile = /etc/postfix/cacert.pem smtpd_tls_received_header = yes tls_random_source = dev:/dev/urandom smtpd_tls_security_level = may
54968
I   that using multiple PTR records in a DNS configuration is not recommended.   However, the reasons are often vague, or not so obvious, naming:    "it can cause problems",  "can trigger bugs in programs expecting a single answer" : it's the software's problem then, isn't it?! "can make DNS answer packet too large" : isn't this fixed with ?   Are these good reasons? Do you know of any other (good) reasons? All this kinda looks like a "legacy fear"...
98764
Client's domain is registered with GoDaddy where they have a mail-only plan at the moment. Now web hosting has been set up elsewhere and we need to point web service to the new host while retaining mail at GoDaddy. (For reasons not important here, this is not negotiable.) What needs to be edited to carry this out correctly?
32325
I am receiving some reports from different clients in Spain, US and France that they cannot access my website, . They get a ERR_NAME_NOT_RESOLVED error saying the server cannot be found.  Personally, I do not get any error and most visitors don't experience it, but one of my clients has been kind enough to send me their traceroute outputs - below. He uses Google DNS in his browser.  I have a shared IP address which made me think it was blocked by an ISP, but it doesn't seem like it is the case. I have contacted Telefonica (which is the last server reached by my client) to ask if they blocked my IP address just in case, but it has been nine days and no response so far.  All website testing programs I've tried cannot seem to find the error. The only red flag I found was that my MX records points to a CNAME. But this is the standard mail settings of my host, .  Could anyone tell me if they cannot access the website and send me the traceroute or do you have any suggestions as to why this is happening? Should I change host just in case?  traceroute to ultreyatours.com (160.153.74.24), 64 hops max, 52 byte packets  1  192.168.1.1 (192.168.1.1)  7.887 ms  2.594 ms  2.378 ms  2  192.168.144.1 (192.168.144.1)  51.844 ms  42.309 ms  41.189 ms  3  * * *  4  26.red-80-58-89.staticip.rima-tde.net (80.58.89.26)  55.877 ms     65.red-81-46-3.staticip.rima-tde.net (81.46.3.65)  54.211 ms     26.red-80-58-89.staticip.rima-tde.net (80.58.89.26)  54.896 ms  5  216.184.113.116.nuevatel.com (216.184.113.116)  51.841 ms  51.221 ms  51.849 ms  6  xe0-0-0-8-grtlontlw1.red.telefonica-wholesale.net (94.142.125.246)  88.292 ms     xe6-1-0-0-grtlontl1.net.telefonicaglobalsolutions.com (213.140.36.254)  94.572 ms     xe-2-0-2-0-grtparix1.net.telefonicaglobalsolutions.com (94.142.117.174)  115.531 ms  7  xe2-0-1-0-grtwaseq6.net.telefonicaglobalsolutions.com (94.142.116.209)  164.105 ms     xe-3-1-4-0-grtwaseq6.red.telefonica-wholesale.net (213.140.36.242)  148.022 ms     xe0-0-1-0-grtnycpt3.red.telefonica-wholesale.net (94.142.126.73)  185.685 ms  8  xe-0-0-2-0-grtnycpt3.red.telefonica-wholesale.net (94.142.126.69)  150.588 ms     dcp-brdr-03.inet.qwest.net (63.235.40.197)  157.253 ms  151.465 ms  9  phn-edge-08.inet.qwest.net (67.14.40.50)  218.708 ms     dcp-brdr-03.inet.qwest.net (63.235.40.197)  163.898 ms     xe3-1-1-0-grtwaseq6.net.telefonicaglobalsolutions.com (5.53.6.145)  178.165 ms 10  xe6-0-6-0-grtwaseq6.net.telefonicaglobalsolutions.com (94.142.116.102)  183.294 ms     phn-edge-08.inet.qwest.net (67.14.40.50)  218.202 ms     63-232-81-254.dia.static.qwest.net (63.232.81.254)  235.276 ms 11  be39.trmc0215-01.ars.mgmt.phx3.gdg (184.168.0.73)  224.855 ms     63-232-81-254.dia.static.qwest.net (63.232.81.254)  255.575 ms     phn-edge-08.inet.qwest.net (67.14.40.50)  227.479 ms 12  be39.trmc0215-01.ars.mgmt.phx3.gdg (184.168.0.73)  230.942 ms     be38.trmc0215-01.ars.mgmt.phx3.gdg (184.168.0.69)  230.278 ms     63-232-81-254.dia.static.qwest.net (63.232.81.254)  235.399 ms 13  * * be39.trmc0215-01.ars.mgmt.phx3.gdg (184.168.0.73)  243.940 ms 14  * * be39.trmc0215-01.ars.mgmt.phx3.gdg (184.168.0.73)  239.542 ms 15  * * * 16  * * * 17  * * * 18  * * * 19  * * * 20  * * * 21  * * * 22  * * * 23  * * * 24  * * * 25  * * * 26  * * * 27  * * * 28  * * * 29  * * * 30  * * * 31  * * * 32  *
81692
I am just analyzing my logwatch logs, and I see the following entries:   SMTP SESSION, MESSAGE, OR RECIPIENT ERRORS  ------------------------------------------   Mail Rejected:        Total:  6   Mail Deferred:        Total:  229   Total SMTP Session, Message, and Recipient Errors handled by Sendmail:  235   ---------------------- sendmail End -------------------------   I only use sendmail for logwatch, so what is causing all these errors, and especially, what are deferred emails.
104008
Here is the problem: From any IP address not belonging to your mail server:  telnet me.myemailserver.com 25    helo me.someserver.com mail from: &lt;yourusername@mydomain.com&gt; rcpt to: &lt;yourusername@mydomain.com&gt; data This is spam.  Buy my stuff. .   I'm using Postfix.  I'm having a problem finding a solution to requiring SMTP-AUTH for email claiming to be from mydomain.com.  Googling around, this guy has identified the same problem (where I cut-n-paste with some modifications) the above example from:   This link   gets close to a solution but it has a side effect of requiring SMTP-AUTH for mail not from mydomain.com.  For mail not claiming to be from mydomain.com, I would do the usual RBL and Spam filtering.  In short, I want to reject mail to local domains (mydomain.com) from outside/unauthenticated clients claiming to be from local domains (mydomain.com).  This is what I tried: I've tried both permit and reject as the default.  Here is exact excerpt from my main.cf:  smtpd_recipient_restrictions = reject_unauth_pipelining,                            permit_sasl_authenticated,                            check_recipient_access pgsql:/etc/postfix/pgsql-recipient.cf,                            reject_unauthenticated_sender_login_mismatch,                            reject_unauth_destination,                            reject_unlisted_recipient,                            check_sender_access pgsql:/etc/postfix/pgsql-sender.cf,                            reject_unlisted_sender,                            reject_invalid_hostname,                            reject_non_fqdn_hostname,                            reject_non_fqdn_sender,                            reject_non_fqdn_recipient,                            reject_unknown_sender_domain,                            reject_unknown_recipient_domain,                            reject_rbl_client cbl.abuseat.org,                            reject_rbl_client sbl.spamhaus.org,                            reject_rbl_client sbl-xbl.spamhaus.org,                            reject_rbl_client bl.spamcop.net,                            reject_rbl_client dnsbl.njabl.org,                            reject_rbl_client blackholes.wirehub.net,                            reject_rbl_client relays.mail-abuse.org,                            reject_rbl_client dialups.mail-abuse.org,                            reject_rbl_client blackholes.mail-abuse.org,                            reject_rhsbl_sender dsn.rfc-ignorant.org,                            (reject and permit both tried here)
109780
We are trying to move all our websites we host to CNAMES as we are planning on moving servers in the new year and would like the ability to move some clients to one server and other clients somewhere else. We were planning on giving clients a unique CNAME which we can then change at a later date. (We have other reasons for doing this now but that is the main one)  We have been testing out this theory with a few of our own domains and it seemed to be fine. However when checking the MX records on a domain I got the CNAME value back rather than the MX record.  Sadly all of these domains are done via control panels, but I am guessing they are just writing zone files for me.  I want to create 2 CNAMEs for the company.com  company.com. IN CNAME client.dns.ourserver.com www          IN CNAME client.dns.ourserver.com   The MX record is something like the following:  company.com  IN MX 10 mail.company.com   We have an A record for mail.company.com  Doing:  host -t mx company.com   Returns the CNAME value rather than the mx record.  Is this expected behaviour?  I have managed to get the above configuration working with the 123-reg.co.uk control panel, but not sure if that is more luck than anything.
26317
Let's say I have a domain that I run a web application on, for example cranketywidgets.com, and I'm using  for handling email for people working on that domain, for example, support@ cranketywidgets.com, jane@cranketywidgets.com, joe@cranketywidgets.com and so on.  Google's own mail services aren't always the best for sending automated reminder emails, comment notifications and so on, so the current solution I plan to pursue is to create a separate subdomain called mailer.cranketywidgets.com, run a mail server off it, and create a few accounts specifically for sending these kinds of emails.  What should the MX records and A records look like here for this?  I'm somewhat confused by the fact that MX records can be names, but that they must eventually resolve to an A record. What should the records look like here?  cranketywidgets.com - A record to actual server like 10.24.233.214  cranketywidgets.com - MX records for Google's email applications  mailer.cranketywidgets.com - MX name pointing to server's IP address  I would greatly appeciate some help on this - the answer seems like it'll be obvious, but email spam is a difficult problem to solve.
97149
I'd like to whitelist several domains in my Postfix configuration in such a way that all e-mails from those domains are accepted as long as they're properly authenticated using SPF and/or DKIM, should it be used by that domain. This means that e-mails coming from those domains should not be subjected to the usual DNSBL and Greylisting process, only to a SPF and DKIM verification.  Right now I have managed to save e-mails coming from those domains from the Greylisting milter by configuring a sender_access file and using the postmap utility to convert it to a suitable hash-database.  main.cf:  ... parent_domain_matches_subdomains = yes smtpd_recipient_restrictions =   permit_mynetworks   permit_sasl_authenticated   reject_rbl_client zen.spamhaus.org   reject_unauth_destination   check_sender_access hash:/etc/postfix/sender_access   check_policy_service unix:private/tumgreyspf ...   sender_access:  domain1.com OK domain2.net OK   I've found out about  and also found a , but it appears like that is a DNSBL-only measure and is only slightly helpful in my case.