Emails to Hotmail.com are disappearing ~ neither delivered nor bounced back.

[#1]

@CSG Our issue is we didn't get any 'bounceback' or non-delivery messages at all. Not in our spam folder, not in our inbox. We only know mail wasn't being received when we were talking to the intended recipient and they confirmed they hadn't received any of the emails we'd sent them 😞

[#2]

We've just now discovered a workround - mail sent from webmail (name@ourplusaccount.plus.com) seems to be delivered to hotmail ok but mail from our mail client (name@ourdomain.co.uk) disappears into the ether.

At least that'll keep us going until we migrate to a new email provider ...

[#3]

@abitpedantic 

Yes ~  outgoing emails to Hotmail which had previously been bounced back to me "disappeared" following the transition to Greenby. However, after  finding them isolated in the Greenby spam filter (via Webmail) and turning the Greenby spam filter off, they are again being bounced back into my email account

Doesn't ,of course, solve the main issue!

[#4]

@balvack2 

We've just now discovered a workround - mail sent from webmail (name@ourplusaccount.plus.com) seems to be delivered to hotmail ok but mail from our mail client (name@ourdomain.co.uk) disappears into the ether.

Unless your domain has a valid SPF record and DKIM signing of your email, then email sent from it stands a good chance of being rejected, particularly by Microsoft & gmail. The anecdotal evidence that NDRs from Microsoft are being discarded by Greenby just exasperates the situation. If you're sending via the Plusnet server then you certainly wont have DKIM signing. You may have an SPF record if you've created one manually in your domain DNS but it will only be a short lived possibility. In the near future, once outgoing mail is routed via the Greenby server, it will not be possible to send from a domain address.

[#5]

Tried several times on Sunday to send to a hotmail address and the attachment contains:

"Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [212.159.14.18] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3140). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [Name=Protocol Filter Agent][AGT=PFA][MxId=11BD0A0C2BBF1E23] [DB1PEPF00039234.eurprd03.prod.outlook.com 2026-03-22T10:05:54.897Z 08DE85061A8D19FD]

Last-attempt-Date: Sun, 22 Mar 2026 10:05:54 +0000

Given that this has been ongoing for several weeks with customers providing plenty of information within reports, please can Plusnet provide an update.  It really should not be taking this long to fix, I believe the move to Greenby was promised to be a "seamless experience."  

[#6]

Thanks @MisterW 

My current SPF record includes the current values for plusnet

spf-internal.plus.net and spf-internal2.plus.net

Can you advise what values I need to add for the Greenby servers please.

Also I believe I can manually add DKIM entries to my domain DNS records. Again, can you confirm what those should be for both plusnet and greenby.

[#7]

@balvack2 

Also I believe I can manually add DKIM entries to my domain DNS records. Again, can you confirm what those should be for both plusnet and greenby.

Whilst you may be able to add DKIM entries, they will be of no use. In order for DKIM to work, the sending mail server must be configured to sign mail for the domain in question. It then generates a private key used for signing and a public key to be configured in the domain DNS.  Neither the Plusnet server or the Greenby server can be configured to DKIM sign mail from external domains.

As for the SPF record value for Greenby, ISTR seeing it detailed somewhere on the forum but I've not researched what it should be and for the moment its irrelevant anyway as mail is still being sent via the Plusnet servers. 

[#8]

With the Hotmail email non delivery notice "non bounce back" issue apparently solved by turning off the Greenby spam filter, ~ may I  clarify advice provided earlier on a suggested temporary fix to the Hotmail email non delivery problem: ~

• I have had a plus.com email account used via MS Outlook Classic version for many years without issues.
• Is it correct that if I create a second Outlook account plus a newly created Hotmail email address then ~ on switching temporarily to this account ~ emails to Hotmail addresses will be delivered and responses received?
• Could I then revert to my plus.com address for the vast majority of my emails? (This would avoid having to notify changes of email address to 90% of my contacts)
• Could the creation of a separate Hotmail address create any other issues?

Thanks.

[#9]

@MisterW 

Re the SPF record - i thought that adding the greenby servers to would possibly resolve the issue I have sending from webmail, as i thought I read elsewhere in one of these threads that outgoing mail from those was already going through greenby not plusnet?

[#10]

@balvack2 

AIUI you can't send mail from an external domain address via the Greenby servers. To allow sending via the Greenby servers, the FROM address in the mail must be either a valid account mailbox or alias name. i.e for a Plusnet account it must be <mailbox or alias>@<accountname>.plus.com 

[#11]

Today, I can again send and receive emails to/from Hotmail email addresses

Are other Plusnet users experiencing the same and does this mean that the issue has been resolved?

[#12]

I successfuly sent an email to a hotmail address yesterday, after many previous failures. (I haven't had any problems receiving from hotmail addresses, only sending to.) Whether this means 'resolution' I'm not qualified to say. I created a hotmail account the other day, specifically for sending to hotmail/outlook addresses when sending from my plusnet address failed. Maybe I won't need to use it after all ... but it'll be there if needed.