Thu, Oct 22, 2020 1:00 PM
4 m ago
Gold Problem Solver
7 m ago
We'd need the text that goes along with the error code, as 421 is associated with several different error conditions, ex:
@Jarita wrote: ... CSI IP 18.104.22.168 is not permitted to send messages. ...
CSI in the error message means the listed IP is blocked by Cloudmark Sender Intelligence. 22.214.171.124 is assigned to Ellijay Telephone Company / ETC Communications (see https://whois.arin.net/rest/net/NET-172-102-160-0-1). Please see https://forums.xfinity.com/t5/Email-Web-Browsing/Can-t-Send-Emails-from-PC-or-Phone-App/m-p/3355422#M219767. Are you using a VPN?
not using VPN
@Jarita wrote: not using VPN
Are you trying to send while using another ISP?
I had similar issues recently when on McAfee VPN that I just started in December. Thought I'd post what worked for me. When on VPN, sometimes I could not send, but always received. It's Comcast ISP and Comcast.net email.
Identified the specific issue: when the VPN was set to 'fastest connection' or words like that, sometimes it would use a foreign location. Last week I saw that it said 'Toronto, Canada' as the location, and it would not send. Sometimes it would say NY or Virginia and emails would send.
So I set the VPN to be USA location and it has worked fine now for a week.
Not sure if that was the fix, or if it was something else because i had been revisiting email account settings in Outlook via Microsoft 365 when it would not send. That said, since tweaking the McAfee VPN location it has worked just fine.