Emails sent to gmail account undeliverable

[#1]

Hey Ian,

That bounceback is familiar and suggests it’s an issue we’ve already carried an investigation into. We weren’t able to fix as it’s due to the way Google’s working.

To confirm if that’s the case, do sent emails via webmail.plus.net to a Gmail address arrive? Additionally is there anything more to the bounceback? Like does it fail SPF/DKIM or advise there’s no valid MessageID? I suspect it’ll be the latter. If so then here’s a link to the outcome of the investigation (it’s not a fix per se)

https://community.plus.net/t5/Email/Help-Emails-I-m-trying-to-send-to-Gmail-accounts-are-bouncing/m-...

[#2]

@Gandalf

Are you able to profile the issue here please?

I believe there’s a clear combination here of…

* Sending to Gmail
* Via relay.plus.net
* Sending from a third party domai address
* Using particular email clients
* Without a SPF record designating relay.plus.net as being a valid sending MX for the third party domain

In such circumstances Gmail will go in a draconian melt down (contrary to RFC specifications) and hard fail the attempted message transfer.

[#3]

Not sure if I’m missing something, we’ve already looked at this. It’s due to the mail client not adding an appropriate MessageID in the header which Gmail accepts. 

This isn’t limited to third party domains but plusnet email addresses in general in format of username.plus.com

[#4]

So the key consideration is particular email clients … even where the from address is @*.plus.com ?

[#5]

I'm sure I have said something similar, but as this topic is getting long, I'll repeat: I am still sending from my @*.plus.com address to a Gmail user on a (at least) daily basis, and have never had a failure yet. (Currently using Thunderbird 102.2.2 on Linux)

[#6]

I am not sure if Plusnet have done something or the rebuilding of my friends computer has fixed the problem of sending emails from a Plusnet account using Thunderbird to Gmail email addresses.

During the computer rebuild I installed the latest version of Thunderbird and the emails are no longer rejected. I copied the original profile into the new installation of Thunderbird so none of the original settings have been changed. I hope this helps anyone looking for help on this in the future.

[#7]

A reinstall and / or an upgrade to the latest version could indeed fix no end of ills!

The failure to generate a MESSAGEID header is a user email application failure.

[#8]

Similar to the post by 'fleckney', I had the issue of not being able to send to any gmail recipients from Thunderbird using Plusnet's SMTP server . I tried uninstalling Thunderbird both with & without an old profile, changing server settings ... nothing made any difference.

So in the end out of frustration I reinstalled Windows 10, then Thunderbird ... and all was fixed.

So in my case the problem was buried in the computer or the something was conflicting between Thunderbird/ Plusnet/ Windows that Google did not like ... perhaps some registry entry.