522 error when sending e-mail (Outlook)

[#1]

My e-mail service (Outlook 2016) has been functioning normally for a long while, with settings unchanged likewise, but today it will no longer send messages, reporting a send/receive error:

"Task 'xxx E-mail - Sending' reported error (Ox800CCC78): 'Cannot send the message. Verify the email address in your account properties. The server responded: 522 Sorry, we couldn't send your message. The network address your device has been assigned is on an industry blacklist to prevent Spam. The problem should be addressed by your network service provider. Please try again later or use webmail.'"

Verification of my e-mail address reports "We couldn't log on to the outgoing (smtp) server"

A remedy would be welcome.   TIA.

Dave.

PS the outgoing mail server is mail.btinternet.com

[#2]

Why not use Plus Net SMTP settings "relay.plus.net", as being on this forum you're presumably
a PN client?

[#3 · Accepted solution]

Thanks for the suggestion, I'll keep it in mind for future.

The problem has been solved by switching the router off for half-an-hour, purportedly to reset the IP address.

[#4]

To avoid presumption, who is your ISP?

Your report of a fix suggests that the IP address was blacklisted and switching the router off for a while resulted in you obtaining a new dynamic IP address. The problem is that you could equally as well get the bad address back again, for in the ‘new’ network IP addresses are assigned form much smaller geographic pools.

[#5]

The e-mail service is BT Internet, with broadband/phone via Plusnet, and is still functioning normally (thus far).