screaming.net smtp issues

[ianfaulkner]

MacOS Sonoma.  I can receive e-mails for my screaming.net e-mail address, but SMTP gives me an error.  Connection doctor shows:
"READ Nov 01 11:29:44.635 [kCFStreamSocketSecurityLevelTLSv1_2] -- host:smtp.talktalk.net -- port:587 -- socket:0x60000036e7c0 -- thread:0x600003ee3c00
453 4.7.0 y9PrqG3B8u8Wd Authentication Denied (TT322)

WROTE Nov 01 11:29:44.635 [kCFStreamSocketSecurityLevelTLSv1_2] -- host:smtp.talktalk.net -- port:587 -- socket:0x60000036e7c0 -- thread:0x600003ee3c00
AUTH PLAIN (*** 56 bytes hidden ***)"

Setup is as per TalkTalk guidance:
Username:  email address@screaming.net
Password: set to same as IMAP
Host Name: smtp.talktalk.net
Port: 587
Authentication: Password
Use TLS/SSL: Ticked

Any ideas?

[ianfaulkner]

Will do.  It is back again now, so fingers crossed.  Thanks for your help.

[Gondola]

I wouldn't expect 12 mail messages to 12 recipients to trigger any alert.

Let me know if you see any other TT error codes as there will be a different set if the sending has been stopped or rate limited for suspicious activity.

[ianfaulkner]

Less than a dozen a day!

[Gondola]

You may have been sending a lot of mail messages? What's your estimate of the number of recipients of your mail messages recently?

[ianfaulkner]

I shall wait and see.  Is this because someone is trying to hack my account?  VERY strong password so unlikely to succeed, but also VERY irritating!

[Gondola · Accepted solution]

It's not  hard fail but you do have a temporary stop on sending because there have been too many attempts to authenticate the sending of mail. I cannot tell if the temporary stop is for an hour or 24 hours so if all does not come good in an hour after the last attempt then you may need to wait and try again tomorrow.