Error message when I use the "reply" button in an email

Mail
1

When I click reply to an email I`m reading I get the following message

[SMTP] Cannot send message (Sending email “Re[2]: Hippodrome Member App” failed with error: ‘From’ field address ‘[email protected]’ not accepted due to the following reason:
"5.1.0 7g57rkaDuw68C MailFrom must match AUTH used (TT421)
")

Does anyone know how to rectify this please?

2

Just a hunch… have you checked Menu > Accounts > SMTP > Authentication to ensure it is filled out correctly?

3

Thanks sunriseal. I have & that checks out. I missed out an important fact in my post. This error only happens with SOME emails & not others.
I guess it`s something to do with the different authorization protocols that different people use.
I can reply in a clunky manner by opening, then sending a new email to the senders address & copy/pasting all previous content to that.
Again, many thanks