Help! Emails I'm trying to send to Gmail accounts are bouncing!

[#1]

I first noticed this happening a week or so ago in respect of one particular email ... In the past 24 hours I've had bouncebacks from 4 different Gmail addresses, with the following error message:

Reporting-MTA: dns; avasout-peh-001 [212.159.14.17]
Received-From-MTA: dns; DESKTOPUH0DUU6 [91.125.68.195]
Arrival-Date: Sat, 28 May 2022 17:36:56 +0100

Final-recipient: rfc822; xxxxxxxxx@gmail.com
Diagnostic-Code: smtp; 550-5.7.26 This message does not have authentication information or fails to

Last-attempt-Date: Sat, 28 May 2022 17:36:57 +0100

If anyone's able to advise - in a way that would be comprehensible to someone not terribly techy! - I'd be really grateful.

For the record, I send emails from my Plusnet address via Outlook (Office 365) on a Windows 10 computer. (Incidentally, I tried sending a test to my own Gmail address, and there was no problem...)

Many thanks in advance!

[#2]

The immediate consideration is are you using authentication on the SMTP server configuration? It should be “use the same as the inbound server”.

[#3]

Thanks, Townsman. I haven't changed any of my settings at all, but I've checked and neither incoming nor outgoing mail have checks against requiring authentication ...

[#4]

CHECKS on authentication is not what you are looking for, but rather that the outgoing (SMTP) configuration is configured to USE authentication.  Inbound MUST use authentication or you would not be able to receive email.

[#5]

SMTP authentication shouldn't be required for a customer of Plusnet to access the SMTP server.

91.125..68.195 is registered to Plusnet.

Looks like a server-side error to me.

[#6]

Since I was forced (i.e. against my will!) to give up Outlook 2010 in favour of Office 365, I can only access email account settings via a 'manual repair' option ... The settings that Outlook insists on inserting are as follows:

These are different to those recommended by Plusnet:

I've tried to manually change the settings to the Plusnet ones but they won't just save ... I've also tried setting up the Plusnet email account again using the Plusnet settings - but it won't work!

In the meantime, I'm still not able to send to several Gmail addresses - although the error's not consistent. One Gmail address at least that I've sent do DOES work!

Really not sure if this is a Plusnet problem or a Gmail problem or an Outlook problem - although I have to say that sending via Outlook from my own Gmail address doesn't seem to be a problem.

[#7]

... it's not conclusive as yet, but it seems as if that the Gmail emails that AREN'T bouncing are where users are still using the googlemail as opposed to the gmail format ...

[#8]

@jjlothin If you use the Mail applet in Windows control panel to configure your email settings you'll find a lot more can be changed.

[#9]

Thanks for that, @Browni - interesting! The settings that come up via control panel are exactly the same as those recommended by Plusnet ...

But I'm still baffled as to why emails to Gmail addresses are bouncing ... but those to Googlemail addresses get through?!?

[#10]

@jjlothin Could be Google playing silly so-and-so's - we've seen this behaviour from them previously, then it stops as mysteriously as it started.

[#11 · Accepted solution]

---

@jjlothin wrote:

But I'm still baffled as to why emails to Gmail addresses are bouncing ... but those to Googlemail addresses get through?!?

---

We have indeed seen this debacle before.  Some emails get through, other only get through after a couple of days.  This is what happened last time...

1. Emails to any Gmail address from a Plusnet user who has their own domain name got through without issue
2. Emails sent from @account.plus.com to a @googlemail address got through without issue
3. Emails sent from @account.plus.com to a PAID FOR @gmail.com email address got through straight away
4. Emails sent from @account.plus.com to a FREE @gmail.com email address were delayed for 24-48 hours or not delivered at all

@bobpullen  - do you have any recollection what was the cause of this please?  I seem to recall that the tech team did something with SPF which might have had some bearing ... but I believe that SPF has been suspended since then.

@jjlothin - the correct setting for the outbound server are...

relay.plus.net port 587 STARTTLS

Using smtp.plus.net and port 25 will work, however, (a) you are likely to encounter certificate validity warnings and (b) port 25 is for MX to MX message transfer, not message submission.

[#12]

Many thanks for that, @Townman - that does seem to be what's happening!

And many thanks for confirming the correct outbound server settings. I've double-checked mine (via Control Panel) and that's exactly what I've got.

I guess I'm just going to have to wait for it all to settle down again - although at least I do know now that I have the option of converting the recipient gmail to a googlemail address.

[#13]

I may be totally off-piste but I'm wondering whether something in the workings of the bowels in the PN mailservers is getting upset with the encoded stuff within in a X-CMAE-Envelope: e-mail header.

[#14]

AFAIK, the CMAE header is added by Plusnet. It's the antispam/virus authority engine we're using.

@Townman - sorry, I don't recall what was done to resolve the issue. I remember trying to keep a watchful eye over things but I'm not sure I was that heavily involved in the resolution.

[#15]

I've also been experiencing Bouncing emails to any GMAIL accounts, all other emails are ok.