How to Fix the PHP Mail Error: \'Multiple or malformed newlines found in additional_header\'?

PHP Mail Error: Dealing with Malformed Newlines in Additional Headers

An enigmatic error, "Multiple or malformed newlines found in additional_header," has recently plagued PHP mail() users. Despite the absence of script modifications, many users have encountered this perplexing issue.

Root Cause

After troubleshooting, it has been discovered that the error stems from a recent PHP security update, which has resolved a vulnerability in the mail() function. Prior to this fix, extra newlines in additional_headers were permissible. However, with the patch in place, these newlines are no longer allowed.

Solution

To rectify the issue, implement the following measures:

• Remove superfluous newlines: Scrutinize your headers and eliminate any multiple newlines in the additional_headers parameter. Specifically, avoid the following patterns: rr, r

The above is the detailed content of How to Fix the PHP Mail Error: \'Multiple or malformed newlines found in additional_header\'?. For more information, please follow other related articles on the PHP Chinese website!