There are a variety of reasons your script appears to not be sending emails. It's difficult to diagnose these things unless there is an obvious syntax error. Without one you need to run through the checklist below to find any potential pitfalls you may be encountering.
Error reporting is essential to rooting out bugs in your code and general errors that PHP encounters. Error reporting needs to be enabled to receive these errors. Placing the following code at the top of your PHP files (or in a master configuration file) will enable error reporting.
It may seem silly but a common error is to forget to actually place the mail() function in your code. Make sure it is there and not commented out.
The mail function takes three required parameters and optionally a fourth and fifth one. If your call to mail() does not have at least three parameters it will fail.
If your call to mail() does not have the correct parameters in the correct order it will also fail.
Your web server should be logging all attempts to send emails through it. The location of these logs will vary (you may need to ask your server administrator where they are located) but they can commonly be found in a user's root directory under logs. Inside will be error messages the server reported, if any, related to your attempts to send emails.
Port block is a very common problem which most developers face while integrating their code to deliver emails using SMTP. And, this can be easily traced at the server maillogs (the location of server of mail log can vary from server to server, as explained above). In case you are on a shared hosting server, the ports 25 and 587 remain blocked by default. This block is been purposely done by your hosting provider. This is true even for some of the dedicated servers. When these ports are blocked, try to connect using port 2525. If you find that port is also blocked, then the only solution is to contact your hosting provider to unblock these ports.
Most of the hosting providers block these email ports to protect their network from sending any spam emails.
When the error suppression operator @ is prepended to an expression in PHP, any error messages that might be generated by that expression will be ignored. There are circumstances where using this operator is necessary but sending mail is not one of them.
If your code contains @mail(...) then you may be hiding important error messages that will help you debug this. Remove the @ and see if any errors are reported.
It's only advisable when you check with error_get_last() right afterwards for concrete failures.
Returns TRUE if the mail was successfully accepted for delivery, FALSE otherwise. It is important to note that just because the mail was accepted for delivery, it does NOT mean the mail will actually reach the intended destination.
If you receive a FALSE return value you know the error lies with your server accepting your mail. This probably isn't a coding issue but a server configuration issue. You need to speak to your system administrator to find out why this is happening.
If your receive a TRUE return value it does not mean your email will definitely be sent. It just means the email was sent to its respective handler on the server successfully by PHP. There are still more points of failure outside of PHP's control that can cause the email to not be sent.
So FALSE will help point you in the right direction whereas TRUE does not necessarily mean your email was sent successfully. This is important to note!
Many shared webhosts, especially free webhosting providers, either do not allow emails to be sent from their servers or limit the amount that can be sent during any given time period. This is due to their efforts to limit spammers from taking advantage of their cheaper services.
If you think your host has emailing limits or blocks the sending of emails, check their FAQs to see if they list any such limitations. Otherwise, you may need to reach out to their support to verify if there are any restrictions in place around the sending of emails.
Oftentimes, for various reasons, emails sent through PHP (and other server-side programming languages) end up in a recipient's spam folder. Always check there before troubleshooting your code.
To avoid mail sent through PHP from being sent to a recipient's spam folder, there are various things you can do, both in your PHP code and otherwise, to minimize the chances your emails are marked as spam. Good tips from Michiel de Mare include:
Use email authentication methods, such as SPF, and DKIM to prove that your emails and your domain name belong together, and to prevent spoofing of your domain name. The SPF website includes a wizard to generate the DNS information for your site.
Check your reverse DNS to make sure the IP address of your mail server points to the domain name that you use for sending mail.
Make sure that the IP-address that you're using is not on a blacklist
Make sure that the reply-to address is a valid, existing address.
Use the full, real name of the addressee in the To field, not just the email-address (e.g. "John Smith" <firstname.lastname@example.org> ).
Monitor your abuse accounts, such as email@example.com and firstname.lastname@example.org. That means - make sure that these accounts exist, read what's sent to them, and act on complaints.
Finally, make it really easy to unsubscribe. Otherwise, your users will unsubscribe by pressing the spam button, and that will affect your reputation.
Some spam software will reject mail if it is missing common headers such as "From" and "Reply-to":
$headers = array("From: email@example.com",
"X-Mailer: PHP/" . PHP_VERSION
$headers = implode("\r\n", $headers);
mail($to, $subject, $message, $headers);
Invalid headers are just as bad as having no headers. One incorrect character could be all it takes to derail your email. Double-check to make sure your syntax is correct as PHP will not catch these errors for you.
$headers = array("From firstname.lastname@example.org", // missing colon
"Reply To: email@example.com", // missing hyphen
"X-Mailer: "PHP"/" . PHP_VERSION // bad quotes
Sometimes the problem is as simple as having an incorrect value for the recipient of the email. This can be due to using an incorrect variable.
$to = 'firstname.lastname@example.org';
// other variables ....
mail($recipient, $subject, $message, $headers); // $recipient should be $to
Another way to test this is to hard code the recipient value into the mail() function call:
mail('email@example.com', $subject, $message, $headers);
This can apply to all of the mail() parameters.
To help rule out email account issues, send your email to multiple email accounts at different email providers. If your emails are not arriving at a user's Gmail account, send the same emails to a Yahoo account, a Hotmail account, and a regular POP3 account (like your ISP-provided email account).
If the emails arrive at all or some of the other email accounts, you know your code is sending emails but it is likely that the email account provider is blocking them for some reason. If the email does not arrive at any email account, the problem is more likely to be related to your code.
If you have set your form method to POST, make sure you are using $_POST to look for your form values. If you have set it to GET or didn't set it at all, make sure you using $_GET to look for your form values.
Some Web hosting providers do not allow or enable the sending of emails through their servers. The reasons for this may vary but if they have disabled the sending of mail you will need to use an alternative method that uses a third party to send those emails for you.
An email to their technical support (after a trip to their online support or FAQ) should clarify if email capabilities are available on your server.
If you are developing on your local workstation using WAMP, MAMP, or XAMPP, an email server is probably not installed on your workstation. Without one, PHP cannot send mail by default.
You can overcome this by installing a basic mail server. For Windows you can use the free Mercury Mail.
In addition to your MTA's and PHP's log file, you can enable logging for the mail() function specifically. It doesn't record the complete SMTP interaction, but at least function call parameters and invocation script.
There are various delivery and spamminess checking services you can utilize to test your MTA/webserver setup. Typically you send a mail probe To: their address, then get a delivery report and more concrete failures or analyzations later:
PHP's built in mail() function is handy and often gets the job done but it has its shortcomings. Fortunately there are alternatives that offer more power and flexibility including handling a lot of the issues outlined above:
Or even the older PEAR::Mail.
All of which can be combined with a professional SMTP server/service provider. (Because typical 08/15 shared webhosting plans are hit or miss when it comes to email setup/configurability.)
Well written, John. I would just add one more thing: Checking the mail server logs of the sending mail server (whether it is locally or remotely hosted), if possible, can often shed light on what is causing the problem. These logs should show 1) whether or not the message was received from the PHP script by the sending mail server and if so, 2) whether or not the receiving MX accepted delivery from the sending mail server.
@mti2935 That's so helpful I am surprised I missed that. I'll be sure to add it that shortly. :)
i would start with dont use mail(), it does such a poor job and is harder to debug than any other mail library
the same website on 000webhost sends emails successfully and fast on netai.net domain but on site88.net i have the same website i get in console that the message sends successfully but i don't receive any messages. Also in comuf.com domain i get error.(The same website on the same host works only on netai.net domain, net16.net works too)
my question (stackoverflow.com/questions/44866673/) was marked as a duplicate of this one, but I still can't figure it out. Any suggestions?