Does message sent with swiftmailer and google account show anywhere in message that swiftmailer was used?

Question

I am wondering if any email recipients may have automatically marked incoming messages as spam, only because swiftmailer was used to send the message (via google smtp, real google account)

Any info on this?

Answer 1

I have been using swift mailer with a gmail account to test sending emails with my web application.

Everything seems to be fine as SwiftMailer sets up the headers properly and none of my emails have ever gone into the spam folder.

When sending multipart emails, swift mailer does insert something into the headers:

multipart/alternative; boundary="_=_swift_v4_13311823894f583b352a1eb_=_

So, yes it is possible to tell if an email is sent using swift mailer as well.