PHP mail() - How to set Priority?

Question

Is there any way to set the priority of PHP mail()? I looked at the online manual but I can\'t find any reference to it.

By priority, I mean High, Normal, Low or 1,

Answer 1

That's usually done by setting following fields in the header:

• "X-Priority" (values: 1 to 5- from the highest[1] to lowest[5]),
• "X-MSMail-Priority" (values: High, Normal, or Low),
• "Importance" (values: High, Normal, or Low).

See the following example (taken from php's mail function documentation):