Recently, many of the e-mails that we send to friends and family are returned with the
message Subject: Mail Delivery Failure
Each rejection begins with:
This message was created automatically by the mail system (ecelerity).
The reasons given for the delivery failure vary:
554 5.4.7 [internal] exceeded max time without delivery (seen most often)
554 p3plibsmtp02-07.prod.phx3.secureserver.net bizsmtp 126.96.36.199 has been temporarily blocked for attempting to mail too many invalid recipients.
550 5.1.0 <188.8.131.52> This IP has sent too many messages this hour.
554 5.7.1 : (RLY:B1) https://postmaster.aol.com/error-codes#554rlyb1
550 5.1.1 Account not available
We did NOT have these delivery failures when we were on Gen4.
All the failed messages were sent to individuals with e-mail addresses that have remained the same for many years.
Our e-mail app is Mozilla Thunderbird, used with both Gen4 & 5, and regularly updated.
Currently, we are on Thunderbird release 52.3.0
Our operating system is Windows10, also regularly updated,
now: Windows 10 Pro, Version 1703 OS Build 15063.540
We tried to send several e-mails reporting this issue to firstname.lastname@example.org
but they were returned with the Mail Delivery Failure explanation:
(while not connected): 554 5.4.7 [internal] exceeded max retries without delivery
Please advise on how to correct this problem.
David & Mary Warner
Thanks for reaching out and providing the error message you received, this helps. I checked on the IP address in question and confirmed that it has been blacklisted for spam, so this is why you are unable to send e-mails. Blacklisting is usually just temporary, depending on who's doing the blocking. You can read more about this in Gwalk's post here.