Submits an email message through PHP's configured mail transport. This guide demonstrates its use in PHP code and explains when the result or side effect needs extra checks.
What It Does
Submits an email message through PHP's configured mail transport.
Syntax and Parameters
The examples below show a real call to mail with suitable arguments. Read the function call in context: its connection, handle, input data or other prerequisites are created before use.
Requirements: configured PHP mail transport; delivery cannot be inferred from a true result.
Example 1: Core Behavior
mail() reports transport submission, not delivery. In production prefer authenticated SMTP with queueing and verification.
<?php
$to = '[email protected]';
$subject = 'Account notice';
$body = 'Your report is ready.';
$headers = ['From' => '[email protected]', 'Content-Type' => 'text/plain; charset=UTF-8'];
$submitted = mail($to, $subject, $body, $headers);
echo $submitted ? 'Submitted to transport' : 'Mail transport failure';Observe the returned value or changed resource state. A successful function call can still require additional checks before a higher-level operation is considered successful.
Example 2: Alternative or Failure Case
mail() reports transport submission, not delivery. In production prefer authenticated SMTP with queueing and verification.
<?php
$to = '[email protected]';
$subject = 'Monthly statement';
$body = 'Your statement is available.';
$headers = ['From' => '[email protected]', 'Content-Type' => 'text/plain; charset=UTF-8'];
$submitted = mail($to, $subject, $body, $headers);
echo $submitted ? 'Submitted to transport' : 'Mail transport failure';Compare the different inputs, environment assumptions or result checks. Do not use a transport-level success value as proof that all business-level requirements were met.
Practical Example: Applying the Rule
mail() reports transport submission, not delivery. In production prefer authenticated SMTP with queueing and verification.
<?php
$to = '[email protected]';
$subject = 'Support update';
$body = 'Your support request was updated.';
$headers = ['From' => '[email protected]', 'Content-Type' => 'text/plain; charset=UTF-8'];
$submitted = mail($to, $subject, $body, $headers);
echo $submitted ? 'Submitted to transport' : 'Mail transport failure';In an application, convert low-level failures into controlled responses and log only non-sensitive diagnostic context.
Important Behavior and Edge Cases
Successful submission does not prove delivery; header injection and address validation must be prevented.
Comparison with Related Functions or Patterns
| Approach | When it differs |
|---|---|
| Submits an email message through PHP's configured mail transport. | |
| Related API or pattern | An SMTP client library offers authenticated transport, retries and richer diagnostics. |
Common Beginner Mistakes
| Mistake | Correct approach |
|---|---|
| Interpreting mail() returning true as confirmed recipient delivery | Successful submission does not prove delivery; header injection and address validation must be prevented. |
| Substituting a related API without checking its semantics | An SMTP client library offers authenticated transport, retries and richer diagnostics. |
Key Takeaways
- Submits an email message through PHP's configured mail transport.
- Successful submission does not prove delivery; header injection and address validation must be prevented.
- An SMTP client library offers authenticated transport, retries and richer diagnostics.
Select this API or pattern based on its documented behavior and the trust boundaries in your own application, and test all external integrations against their actual deployments.