Error message 554 5.7.1 (P4) Message Blocked due to Spam Content
Thunderbird was working fine for a number of years, and then out of the blue I get this error message when I try to send e-mail: The Mail Server responded 554 5.7.1 (P4) Message Blocked due to Spam Content in the Message.
Nothing has changed...no additions or changes to my Thunderbird e-mail. These are one on one e-mails I'm trying to send...no group mailings. My carrier is RCN and I can send e-mail from my RCN webmail address. I can receive mail with no trouble. RCN claims it's not their issue. BUT.....I also have a Samsung Galaxy 7 phone with an ANDROID OS. I get a similar error message on my RCN e-mail account on the phone. Two totally separate devices....different OS....but same problem. I have changed nothing on the phone...heck I can hardly figure out how to answer an incoming call let alone mess around with e-mail settings. I have two other e-mail accounts on the same desk top computer and phone that both work fine...one is a Yahoo account, and one is a Verizon account. I'm not a high level tech with these devices...please make suggested remedies as simple as possible. Thanks very much....Bob
Chosen solution
Another option, that might avoid the RCN-rejection issue, is to send from the RCN account, but through the Yahoo smtp. Like with gmail, you add the RCN account as a verified or authorized sending account, so recipients see your messages as sent from RCN, even though they went through a non-RCN smtp. Add the RCN account to Yahoo via Yahoo webmail settings (and receive the validation email), then in TB, select the account in the left pane of Tools/Account Settings, and choose the Yahoo smtp in the Outgoing Server (SMTP) drop-down in the right pane.
https://clickwp.com/p/yahoo-mail-alt-address/
Yahoo smtp settings are: smtp.mail.yahoo.com on port 465, SSL/TLS, authentication = OAuth2.
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I managed to find the configuration editor and changed "mail.stricly_mime" from false to true. I thought that did the trick, but just got a message back from an e-mail recipient that the question marks are still there. What's the next step? Thanks. Bob
Not sure if it matters, but did you restart TB after changing the preference?
Not sure if I restarted TB after changing the preferences. I changed them yesterday and sent the message yesterday. I'll send another test message tonight and see what happens. I'll let you know what happens. Thanks. Bob