Email send fails / SMTP Certificate

[#1]

Thanks all - we've flagged this for investigation.

James

[#2]

So, if I've understood, the phone being out of support from the manufacturer is the issue.
So far, I've got the Gmail app sending again but there's still a problem with synching (I think) which is resulting in the sent folder being empty and sent messages not being saved. That was done by changing to "accept all certificates", presumably including out of date ones.
My go-to email client is Outlook for Android and there I can't edit the account settings. It seems once set they can't be changed. I'll have to delete the account and try starting again.

[#3]

@Dalesman

If your email has migrated to Greenby try with mail server : mail.enmail.co  

it works for POP3 / IMAP / SMTP & Certificate Check is passing for me in Blue Mail and Gmail.

[#4]

@Dalesman 

"So, if I've understood, the phone being out of support from the manufacturer is the issue."

Yes and No!

Yes: in that some manufactures are not updating older devices with current standard root security certificates.

No: in that Plusnet does not necessarily need to use the latest - best practice - current standard root security certificates, but it is wise to do so.

The issue has arisen due to the SSL certificates having recently been reissued; the quandary is why were inbound servers issued with G2 root certificates (which is why they still work on older devices) but outbound servers (for Plusnet / Force9 / Free-online) were issued with G5 root certificates.

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@PhilipHeyes wrote:

@Dalesman

If your email has migrated to Greenby try with mail server : mail.enmail.co  

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Good call - that server uses a different root certificate authenticator ...

Subject:CN=mail.enmail.co
Issuer:C=US, O=Let's Encrypt, CN=YR2
Version:2
Serial Number:05:f4:33:c1:7a:9d:f2:c7:b6:e0:7a:0a:71:ba:39:fa:2d:f4:
Signature Algorithm:sha256WithRSAEncryption
Start Date:2026-08-06 14:30:19 GMT
Expire Date:2026-11-04 14:30:18 GMT

Public Key Algorithm:rsaEncryption
RSA Public Key:2048

Subject:C=US, O=Let's Encrypt, CN=YR2
Issuer:C=US, O=ISRG, CN=Root YR
Version:2
Serial Number:4e:bd:24:94:7e:24:d3:94:80:2d:84:a5:2f:d5:b3:19:
Signature Algorithm:sha256WithRSAEncryption
Start Date:2025-09-03 00:00:00 GMT
Expire Date:2028-09-02 23:59:59 GMT
Public Key Algorithm:rsaEncryption
RSA Public Key:2048

Subject:C=US, O=ISRG, CN=Root YR
Issuer:C=US, O=Internet Security Research Group, CN=ISRG Root X1
Version:2
Serial Number:00:f2:4b:6d:17:f9:d9:ad:7c:b1:c9:fe:a7:87:82:69:9f:
Signature Algorithm:sha256WithRSAEncryption
Start Date:2026-05-13 00:00:00 GMT
Expire Date:2032-09-02 23:59:59 GMT
Public Key Algorithm:rsaEncryption
RSA Public Key:4096

That looks to be allowing two root certificates to be used.

[#5]

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@James_B wrote:

Thanks all - we've flagged this for investigation.

James

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Hi @James_B 

What priority please and is there an ETA for investigation... This dragged on a bit last year, which is why I have the divisional escalation history.  For some, this makes their mature devices not much more useful than a paper-weight.

Hard rock and sea space ... on the one hand I can understand why Plusnet might seek to drop the deprecated G2 standard and adopt something better (G5) but why do it only on the outbound server, not everywhere?

Again, we have hit this painful issue on a weekend - is this being investigated by 24/7 support staff?