PHP mail() fails to send mail to same domain name as server
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In terms of UX what do you guys think is the best approach when integrating a trial period for subscriptions?  My application offers a 15 day trial, at the minute the user can sign up without providing any payment information (Paypal Subscription). The account is then set to trial status and after 15 days the user will be redirected to an upgrade page.  Do you think this is the best approach? I am unsure whether or not to let Paypal manage the trial, this however means that the user will need to go through the Paypal payment system during signup. I think this may put some people off signing up.  On the other hand this approach may increase the number of conversions to a full account. Should you use "who" or "that" when talking about multiple people doing something? Which of the following is correct?        There were 10 people that went to the store.   There were 10 people who went to the store.      Edit:  Which of the following is correct?        There were 10 people that had brown hair.   There were 10 people who had brown hair. CAST and IsNumeric Why would the following query return "Error converting data type varchar to bigint"?  Doesn't IsNumeric make the CAST safe?  I've tried every numeric datatype in the cast and get the same "Error converting..." error.  I don't believe the size of the resulting number is a problem because overflow is a different error.  The interesting thing is, in management studio, the results actually show up in the results pane for a split second before the error comes back.  SELECT CAST(myVarcharColumn AS bigint)   FROM myTable   WHERE IsNumeric(myVarcharColumn) = 1 AND myVarcharColumn IS NOT NULL   GROUP BY myVarcharColumn   Any thoughts? If $p\in\Bbb Z[X]$ show that: $ \max\limits_{x\in [0,1]}\left|p(x) \right| > \frac{1}{e^{n}}. $ This is problem 10 from the International Mathematical Competition for University Students of 2015, from day 2, in Bulgaria. I think it is an interesting problem!     Let $n$ be a positive integer, and $p(x)$ be a polynomial of degree $n$ with integer coefficients. Prove that   $$ \max_{x\in [0,1]}\left|p(x) \right| &gt; \frac{1}{e^{n}}. $$   Proposed by Géza Kós, Eötvös University, Budapest. Solve Euler Project #9 only mathematically - Pythagorean triplet The "Euler Project" problem 9 () asks to solve:  $a^2$ + $b^2$ = $c^2$ a + b + c = 1000  I find answers solving it with brute-force and programmatically, but is there a way to solve the problem ONLY mathematically? Can someone help, please?  Problem as explained in Project Euler website:  A Pythagorean triplet is a set of three natural numbers, a &lt; b &lt; c, for which,  a^2 + b^2 = c^2 For example, 3^2 + 4^2 = 9 + 16 = 25 = 52.  There exists exactly one Pythagorean triplet for which a + b + c = 1000.  Find the product abc. Now that the , I've been seeing tag-only suggested edits from 1500-rep users.  For example, one had the summary of 'burninating [tagThatWasRemoved]'.  It's very tempting to reject these as Too Minor, but I know that these users used to have a Retag privilege (and are obviously trying to participate in a burnination.)  What should we do for tag-only edits from high(er) rep users? This is a generic inquiry on the common practice/standard for determining the acceptable values of RMS when georeferencing topographic maps.  Is there an absolute value?  Some literature suggests that it should be "less than or equal to 1/2 of the side of a cell which make up the total resolution of the image." markdown doesn't work properly Is $[0,1]$ a countable disjoint union of closed sets? Executing SSIS 2012 package that has script components from external application OS keyboard shortcuts conflict with apps keyboard shortcuts in GNOME 3 Is gravitational time dilation different from other forms of time dilation? Is gravitational time dilation caused by gravity, or is it an effect of the inertial force caused by gravity?    Is gravitational time dilation fundamentally different from time dilation due to acceleration, are they the same but examples of different configurations?    Could you recreate the same kind of time dilation without gravity using centrifugal force? Conventional parenting wisdom tells us to drive the fear of talking to strangers into our kids. Is this at all harmful though? Is there any adverse impact to a child's social development by doing this? How can you balance safety against fear? Instantiate a class with or without parentheses? Quickest way to rename files, without retyping directory path I have a land cover classification derived from Landsat TM imagery - I created this classification using ENVI. I would like to edit individual and groups of cells in some areas of the classification in order to improve the accuracy of the output by comparing it with aerial imagery.  Is there a way, using ArcGIS Desktop, to manually edit large groups of cells by selecting them and assigning them to a new or existing class?   I am aware of merging methods based on class statistics, but the area I'm classifying has a high amount of spectral confusion due to thin cloud cover - it seems like a manual edit is the only way to go. Why, microscopically, is the voltage drop across a resistor affected by the current through it? If voltage is a potential difference, describing how much energy will be lost per unit charge as charge carriers pass through the resistor, why would the rate at which charge flows (i.e. current, $=dq/dt$) affect the amount of energy lost per unit charge?  I suppose I am asking why a quasi-"extensive" property of the system (current) would affect a quasi-"intensive" property of the system (voltage drop across the resistor).  Apologies if the answer is obvious; I was having trouble understanding why the rate of charge flow would factor into voltage drop whilst trying to rationalize Ohm's law for myself. How do I add a launcher for .sh applications? I have installed ubuntu (11.04).  I installed phpstorm which is simply an archive for you to extract and shove in your /opt directory.  To run it you would use /opt/PhpStorm-103.243/bin/PhpStorm.sh  In unity I had created a launcher on my desktop.  Now I have installed gnome-3(gnome-shell),  And I have nothing in my desktop.  So how do I run phpstorm quickly? Can I get it to show up in "applications"? I tried to write , but I couldn't find any simple explanation page to link to. I ended up garbling a home-spun description of my own with a not-terribly-helpful image from 2012.  This  puts it better than I can:     As a new user in 2015 can there please be more information about what is WinterBash. The link took me to a bunch of stick figures running around making (I think) numbers (I think its a countdown clock). It doesn't explain the event or even what a hat is. – Ian Miller Dec 4 at 2:58   All I found on Meta was dead links. For example,  was downvoted to -2 and answered with a link to an FAQ page that no longer exists. How to hide TabPage from TabControl