Mail can't verify the identity of the server 'imap.plus.net"

[#1]

You need to look at the detail of the certificate payload in one of the links posted earlier.  One could just accept (trust) the certificate.

[#2]

@Townman Agreed, and no harm would be caused.

[#3]

@Tina11192 

Thank you - private message sent.

[#4]

@Townman @jab1 

There was an option to do this in the 'not trusted' message that appeared in the Mail app, as per the screengrabs that I posted originally.  After reading various replies, I took this course and can now send and receive emails on my desktop Mac.

However, I'm getting the same issue on my iPhone in the Mail app, and there's no apparent way of taking the same action there. 

Awaiting the Support Team's findings with interest...

[#5]

Just checked the iPhone we have in the household:

IOS 16.6.1
Trust Store Version 2023032800
Trust Store Version 1006

Currently this device is recieving and sending emails

However according to the official list of what this trust store contains I can't see a G5 root certificate from DigiCert in it (only text search hit is the Verisign one)

https://support.apple.com/en-gb/102666

[#6]

UPDATE:  I was misreading the situation.  I have two active plusnet email accounts/addresses.  The action of trusting the new certificate in Mail on my desktop Mac has resolved the issue for both accounts on my desktop.  It also seems to have resolved the issue for my primary account in Mail on my iPhone.  The message that I was seeing on my iPhone and which made me think both mail accounts were erroring in fact only referred to the secondary mail address/account.  That error has persisted for the secondary account on my iPhone but is no longer present for that account on my desktop Mac.  I can't see a way of correcting this on the iPhone.

[#7]

Hi I am receiving my emails on all my hardware except my iPad, I am receiving the following error.

ive checked my settings on my iPhone etc and all the same as iPad, this just happened over the weekend .

Can anyone advise please

[#8]

Same problem here with an Apple device not liking the Plusnet server certificates all of a sudden. Just to add weight to current theory...

iPhone running iOS 18.6 and Apple Mail IS collecting Plusnet mail (via IMAP). ✅

Mac running MacOS 14.7.7 and Apple Mail IS NOT collecting Plusnet mail (via POP). ❌

[Note that iOS 18 is the current/latest version, but MacOS 14 is not. Although 14 is only one version behind, and still supported by Apple.]

[#9]

Thank you so, so much for this fix!

I was initially blaming Plusnet for what I hoped was just a temporary glitch, and waited hours & hours for things to put themselves right.  And then it gradually dawned on me that the fault lied with Apple Mail.

I'd just about given up, and was ready to ditch Apple Mail in favour of a different email client.  I'm not particularly computer savvy (and I'm usually pretty anxious about changing system settings - especially when previously things had worked OK) - but I followed your instructions - and hey presto!

I'm just really really angry about Apple leaving us users of older computers completely high and dry like this  ...or is it perhaps partly Plusnet's fault as well? - I'm just not sure any more!  Thanks again anyway.

[#10]

Thank you so, so much j123 for this fix!

I was initially blaming Plusnet for what I hoped was just a temporary glitch, and waited hours & hours for things to put themselves right.  And then it gradually dawned on me that the fault lied with Apple Mail.

I'd just about given up, and was ready to ditch Apple Mail in favour of a different email client.  I'm not particularly computer savvy (and I'm usually pretty anxious about changing system settings - especially when previously things had worked OK) - but I followed your instructions - and hey presto!

I'm just really really angry about Apple leaving us users of older computers completely high and dry like this  ...or is it perhaps partly Plusnet's fault as well? - I'm just not sure any more!  Thanks again anyway.

[#11]

@Tina11192 I have pm'd you with the same issue 🙂

For others who may be interested, my  Mini ipad (4), ios version 17.3.1 isn't receiving mail

my iphone 13, ios 17.6.1 is but not from all mailboxes

[#12]

I cannot see any update or response. 🤔

[#13]

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@John46 wrote:

I'm just really really angry about Apple leaving us users of older computers completely high and dry like this  ...or is it perhaps partly Plusnet's fault as well? - I'm just not sure any more!  Thanks again anyway.

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Depends on how you define "fault".

Sure Plusnet has updated its security certificates, which are issued by a third party who use current root certificates to sign them.  Apple has not released current root security certificates (used to verify the certificates) to various platforms, particularly the mature ones.

Is keeping system security certificate signing current a "fault"?

[#14]

Same problem here:  email works find on my iPhone (IOS 18.6),  but not on my MAC (running macOS 13.2.1), using Mac Mail.

It stopped working in the early hours of Monday 11th.   

Same error message as other have reported:  'Mail can't verify the identity of the server "imap.plus.net".

I've made no changes to my Mac or mail configuration recently...the're stable and working fine for a number of years.

Surprised to see no response or fix from Plusnet.

[#15]

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@John46 wrote:

Thank you so, so much j123 for this fix!

I was initially blaming Plusnet for what I hoped was just a temporary glitch, and waited hours & hours for things to put themselves right.  And then it gradually dawned on me that the fault lied with Apple Mail.

I'm just really really angry about Apple leaving us users of older computers completely high and dry like this 

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@KarenB2 / @chalkridge 

There is not going to be a fix from Plusnet as the source of the problem is elsewhere.