Can't send emails when connected to Time Capsule

[tatty27]

I have 3 emails accounts I have used regularly for the past 3 years, 2 pop mail that use SMTP servers and one IMAP (Outlook.com). All of the mail accounts can receive emails without an issue but one of the POP mail accounts has decided that it can't send any more, the outgoing email just sits in the outbox until eventually the OS gives up. The reason why I say OS rather than specify is because this behaviour started happening on 4 devices at the same (iMac and MacBook Pro both running El Capitan and iPhone 6 and iPad Pro, all of which are fully updated).

I have spent hours trying every combination of settings I could until I had to leave to go and visit the folks so I took my iPad and iPhone with me so I could carry on messing about with it and to my surprise both devices sent emails seamlessly while connected to their wireless network with the setting I knew should work but as soon as I got back home and connected to my wireless network (Time Capsule) they stopped again. To test I disabled the wireless connection on both devices and they sent just fine again via 4G.

It would now seem that the issue is the wireless configuration here but what I don't understand is that the Time Capsule has been used for the past 4 months without issue and I haven't changed anything on it?

The only thing I can add is that 2 days ago I had to reinstall the OS on the iMac after it wouldn't boot after running a Clean my Mac scan (never again!) but the mail was definitely working before then but surely that wouldn't affect the other 3 devices too?

 

[Alrescha]

As an alternative view, I see that it works when you are away from home, but not when you are home. Some ISPs insist that you only use their outgoing mail servers - is it possible that they have changed the rules on you?

A.

 

[tatty27]

As an alternative view, I see that it works when you are away from home, but not when you are home. Some ISPs insist that you only use their outgoing mail servers - is it possible that they have changed the rules on you?

A.

Neither of the accounts that are working use my ISP's outgoing servers.

 

[Alrescha]

Neither of the accounts that are working use my ISP's outgoing servers.

OK. What does Connection Doctor (Mail: Window/Connection Doctor) say on OS X? Is there anything interesting in the logs (you can get to them from C.D.)

A.

 

[tatty27]

OK. What does Connection Doctor (Mail: Window/Connection Doctor) say on OS X? Is there anything interesting in the logs (you can get to them from C.D.)

A.

CD says it couldn't connect to this SMTP server, check my network connect and check I entered the correct information and the log says:

READ Feb 22 00:38:15.205 [kCFStreamSocketSecurityLevelNone] -- host:mail.clarkdental.co.uk -- port:587 -- socket:0x7fcf5157d290 -- thread:0x7fcf56c448a0
421 Server is busy, try again later.
CONNECTED Feb 22 00:38:15.228 [kCFStreamSocketSecurityLevelNone] -- host:mail.clarkdental.co.uk -- port:587 -- socket:0x7fcf5157d290 -- thread:0x7fcf56c448a0

READ Feb 22 00:38:15.249 [kCFStreamSocketSecurityLevelNone] -- host:mail.clarkdental.co.uk -- port:587 -- socket:0x7fcf5157d290 -- thread:0x7fcf56c448a0
421 Server is busy, try again later.

 

[Alrescha]

421 Server is busy, try again later.

That is the mail server on the other end, telling Mail to try again later. The good news is there is nothing obviously wrong with your Time Capsule. You may need to talk to your email provider.

A.

 

[tatty27]

That what I thought, but what doesn't make sense but if I disconnect from the wireless network and use 4G instead it works with no changes made to the settings
[doublepost=1456102619][/doublepost]OK, I now know it isn't the Time Capsule because I have just re-enabled the wireless interface on my Internet router and it won't work when I'm connected to that instead of the Time Capsule.

 

[Alrescha]

That what I thought, but what doesn't make sense but if I disconnect from the wireless network and use 4G instead it works with no changes made to the settings

Understood. "Server is busy" is generic, and possibly untrue. It may have something to do with your IP address. (1)

A.

 

[tatty27]

I'll reboot my router and see if that helps
[doublepost=1456104217][/doublepost]Nope, no difference. Well, I can send if I use the Outlook IMAP server for sending mail so that will have to do until tomorrow because it's bed time now. Thanks for your help