When 'Use Reply-To header' is checked, two reply-to headers are sent out (Reply-to and Reply-To). This looks like this (supplied name and supplied address are pulled from the webform):

Reply-to: "<supplied name> via <webform from name>" <webform from address>
Reply-To: "<supplied name>" <supplied address>

It seems that different email clients handle this in different ways. Most pertinently, it seems that when replying to the email from an iPhone (iOS9) the email is not sent to the supplied email address.

The webform_reply_to module still works fine with this and sends

Reply-to: "<supplied name>" <supplied address>

I can't find Reply-to (lower case t) in the code, just Reply-To so I'm thinking something else might be interfering with this but I've no idea what nor why it wouldn't do the same when the webform_reply_to module is used. I'm not using any mail modules that might hook in. Any ideas?

Comments

danwonac created an issue. See original summary.

DanChadwick’s picture

Status: Active » Closed (works as designed)

Some other module is setting the "Reply-to" header. Webform sets that as the "From" header. And it sets the capitalized "Reply-To" header. I've searched the codebase and no where does it set "Reply-to". The correct header is "Reply-To". See the RFC: https://tools.ietf.org/html/rfc5322#section-3.6.2

Please reopen if you find information to the contrary.

mrP’s picture

For anyone else that stumbles on this, Sendgrid was blocking email with SMTPAPI duplicate reply-to headers warning. Turns out, Drupal 7 core as of 7.71 still set "Reply-to" in includes/mail.inc.