I have had to revert to version 2.4.3 of the plugin to get it working. The 2.4.4 update breaks the authentication and says there is no authorised sender.
I can’t provide any additional information right now but I am confirming this. Version 2.4.4 fails to send with Sendgrid because of “sender verification” error. Rolling back to 2.4.3. resolved for me. Can try to provide more information later.
Including a session transcript from an example failed message. (Side note: We can’t include text only visible to plugin authors anymore?)
smtps:plain://smtp.sendgrid.net:465
220 SG ESMTP service ready at geopod-ismtpd-11
EHLO mydomain.com
250-smtp.sendgrid.net
250-8BITMIME
250-PIPELINING
250-SIZE 31457280
250-AUTH PLAIN LOGIN
250 AUTH=PLAIN LOGIN
AUTH PLAIN
334
MyAPIKeyIHaveRemovedForPostingToTheSupportForum
235 Authentication successful
MAIL FROM:<[email protected]>
250 Sender address accepted
RCPT TO:<[email protected]>
250 Recipient address accepted
DATA
354 Continue
X-Mailer: Postman SMTP 2.4.4 for WordPress (https://ww.wp.xz.cn/plugins/post-smtp/)
X-WPCF7-Content-Type: text/plain
Content-Type: text/plain; charset=UTF-8
From: My User <[email protected]>
To: [email protected]
Message-Id: <[email protected]>
Subject: Our Subject
Date: Fri, 10 Mar 2023 18:05:04 +0000
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
MIME-Version: 1.0
Customer [email protected]
.
550 The from address does not match a verified Sender Identity. Mail cannot be sent until this error is resolved. Visit https://sendgrid.com/docs/for-developers/sending-email/sender-identity/ to see the Sender Identity requirements