Implementation of Reply-To header in Gmail

Question

Gmail has always ignored the Reply-To header in the e-mail generated by contact forms submitted from my web site. So when I try to reply a message like this:

From: webmaster@example.com
To: webmaster@example.com
Reply-To: user@example.net

... I get a compose window with webmaster@example.com as recipient. I don't normally notice the error until I get my own message back.

The funny thing is that Gmail actually implements the header but the implementation is buggy. The bug appears to be related to using your own e-mail address (i.e., you don't hit it in e-mail for third-parties).

My questions is whether someone has found an official statement about the issue or, at least, some specs about how it's implemented. The info I've gathered in Google help and forums is far for complete.

Answer 1

Apparently, this is still an issue. Definitely feels like a bug.

Interestingly some email clients do something similar ...

Yes, if Thunderbird recognises the reply as a follow-up, it ignores the Reply-to (or, at least, it did the last time I tested it).

... however I agree that if the Reply-To header is there, it should be honored in all cases

bkennelly claims that, based on the assumption you intended to follow up to a message you sent, the software "preserves, rather than reversing, the address headers." However, this isn't actually what Gmail does in the issue discussed here. Remember that this Gmail behavior occurs whenever the "From:" header in the received message matches any of your "Send mail as" addresses, although it isn't necessarily the address that the message was sent "To" or the default address for your account. Then, when you click "Reply," Gmail preserves the "To" of the original message but not the "From" of the original message. This shows further that it's a bug -- not a deliberate attempt to preserve headers of the original message.