This page documents the FIXED_SENDER configuration setting in FormMail.
Type Of Setting
FIXED_SENDER is an OPTIONAL setting, which means...
OPTIONAL : you can change this setting if you need to, but the default value is fine for most circumstances.
Sets a fixed email address for sending form results.
Set FIXED_SENDER to the email address you want as the sender of form results.
Some email servers will refuse to send an email if the sender is not an email address in your domain. Note that the sender is a different concept to the From address in an email, even though they are usually the same.
Note that FIXED_SENDER is only used for form results, not alert messages. For alert messages, you can set the From address and the sender together with the FROM_USER setting.
When a form is submitted, most website owners want the From address to be set to the email address of the person submitting the form. FormMail does this automatically by utilizing the value of the email special field.
In some cases, the email server assumes the From address is also the sender and, as mentioned above, some email servers will refuse to send you email if the sender is an unknown email address. FIXED_SENDER allows you to set a specific email address as the sender without affecting the From address in the email.
For detailed information about how FormMail specifies the From address and Sender address of emails, view the detailed document about From Address and Sender.
$FIXED_SENDER = "";
$FIXED_SENDER = "firstname.lastname@example.org";