verp documentation is incorrect
Created by: ian-kelling
https://docs.civicrm.org/sysadmin/en/latest/setup/civimail/#bounce-processing
In the section titled VERP Support, the sentence that says "VERP can be disabled via the option Track replies using VERP in Reply-To header at Administer > CiviMail > CiviMail Component Settings. This will reduce CiviCRM's ability to correctly match bounced messages." is wrong.
That setting adjusts the Reply-To header, which is completely different than an envelope return path. I use civicrm with the standard sendmail GNU/Linux method, civicrm sets a VERP without that setting checked.
For the setting in question, the civi UI says "[x] Track replies using VERP in Reply-To header If checked, mailings will default to tracking replies using VERP-ed Reply-To. "
So, I will call it the "VERP-ed Reply-To" setting. It's copying the VERP into the reply-to. Why it does this? I don't know, I would like to know. I have it disabled and VERP is working and bounce processing is working. Perhaps some third party email services copy the reply-to into the envelope return path? If you are using sendmail like me, it seems like turning it on would only hurt in identify bounces, because it would make legitimate replies (not bounces) go to the VERP address.
If possible, what the reply tracking is for should be documented, but saying that it "disables VERP" is definitely wrong and needs to be changed. It disables "VERP-ed Reply-To", not VERP.