Bounced back emails
Thunderbird just did an update. Now my emails to certain domains bounce back (such as hotmail.com; me.com and other private .ca email addresses) Emails to Gmail, Yahoo, Telus, and other private .ca were delivered. Diagnostic-Code: smtp; 554-perfora.net (mxeueus004) Nemesis ESMTP Service not available Diagnostic-Code: smtp; 550 5.7.1 Mail from IP 64.59.136.138 was rejected due to listing in Spamhaus XBL. For details please see http://www.spamhaus.org/query/bl?ip=64.59.136.138 Diagnostic-Code: smtp; 550 5.7.1 Service unavailable, Client host [64.59.134.13] blocked using Spamhaus. To request removal from this list see https://www.spamhaus.org/query/ip/64.59.134.13 (AS3130). [DB8EUR05FT052.eop-eur05.prod.protection.outlook.com] Wary of following spamhaus links.
Opaite Mbohovái (2)
Those bounced messages have absolutely nothing to do with Thunderbird. The update is just coincidental. As you noted, emails are getting delivered, except those that are getting rejected on the recipient's end. You should follow those spamhaus links. They tell you what you need to know about the blocked host and why it was blocked in the first place. That IP was blocked because of its listing here https://www.abuseat.org/lookup.cgi?ip=64.59.136.138. Give that a good read.
Thank you for your reply. Read the link but too technical for me. =( Decided to give it a try, and without making any changes, sent the emails. And so far no bounced back emails! Thanks for taking the time to share your knowledge.