E-mail sending from phone weirdness - have outgoing server settings changed?

[#1]

As of yesterday I can no longer send e-mails from my phone when I am connected to my home Plusnet WiFi, but I can when connecting through Vodafone.

I am using these server settings below. They test OK but the e-mail just sits in my out box.

SMTP Server: relay.plus.net

Port: 587

Security type: STARTTLS

Require sign in: Yes

Has something changed whereby I now need different settings depending on whether I am connected to the internet via Plusnet or Vodafone?

Incoming mail appears to be unaffected.

[#2]

Default mailbox or secondary mailbox?

Username credentials - email address or account name?

Confirm this is the Plusnet brand email (not one of the various legacy brands).

What is the EXACT failure message please?

[#3]

Default mailbox or secondary mailbox? Secondary (I have more than one secondary account, all seem to be affected)

Username credentials - email address or account name? e-mail address.

Confirm this is the Plusnet brand email (not one of the various legacy brands). Not sure what you mean here but these are the same Plusnet e-mail addresses I have used since becoming a Plusnet customer.

What is the EXACT failure message please? There is no failure message.  The phone shows "sending mail" for a few seconds as normal but the mail simply doesn't leave the outbox on my phone.

[#4]

Can you send email from any other device at home?

If this works via a mobile network connection, but not over your home wifi the that points to a 'local' issue, be that your allocated IP address or something not right with the WIFI connection.  However I guess that otherwise the phone works fine?

Which phone / OS version / email application?

When did your router last disconnect and reconnect to the internet?

If you have computer at home, can you please run the email server connection diagnostics - see link below.

[#5]

....and it just randomly started working again without me changing anything.

Will post again in this thread if the issue reoccurs.

[#6]

Keep a watch on this.

The timing of this starting to work again is 'interesting'.  There is a volume / quota issue at the moment which I have escalated to the business; this shows on most clients as a 'too many sent items' NDR RESPONSE.  I wonder if it is possible that some email clients get stuck in these circumstances.  The quota is reset on the hour ... so yours now working is a little coincidental.

[#7]

Can you send email from any other device at home? Yes, from my PC. However my PC uses a wired ethernet connection, in case that is relevant.

If this works via a mobile network connection, but not over your home wifi the that points to a 'local' issue, be that your allocated IP address or something not right with the WIFI connection.  However I guess that otherwise the phone works fine? All internet related apps on my phone are working fine.

Which phone / OS version / email application? Huawei P20

When did your router last disconnect and reconnect to the internet? A couple of days ago after a power outage.

If you have computer at home, can you please run the email server connection diagnostics - see link below. Will get into this if it stops working again, but right now the issue seems to have resolved itself.

[#8]

There is a potential explanation here - IP address poor reputation - and a series of IFs...

• If when the router restarted a few days ago, it got allocated a dirty IP address
• If you had not tried to send emails from your PC at all through this time
• If you have not tried to send from your phone on network until yesterday
• If the dirty IP address quarantine has lifted (usually 48 hours)

Then what you report is very plausible.

The email server connection diagnostics would have detected this, if run at the time.  They are a very helpful go to diagnostic, which saves a good deal of time fiddling with email client settings.

[#9]

Well I certainly hope it's not that as I have a fixed IP address

[#10]

That is VERY helpful - I will run another test and report back.  I have a different theory!

EDIT: That theory does not hold water - this is not connected to the too many recipient issues being reported elsewhere.