Using 3BB, sending emails over smtp.tttmaxnet.com results in error 421 since yesterday 6pm. Have they made any changes?

If anyone else is running into this issue: apparently they opened port 25 and use of the SMTP server from your mail provider is recommended. It is also possible to use smtp.3bbmail.com with the credentials you have registered at member.3bb.co.th. The server smtp.tttmaxnet.com will be taken offline some day.

The error is: 421 - The service is not available and the connection will be closed.

This could be a temporary outage of the smtp server, or a possibly permanent one.

From one smtp server to another, the send will try for up to 3 days. If you're using a mail program, it will probably not retry.

Some people will try to send spam on any link and any open relay server they find.

I have heard this problem from a number of users recently. I had a real "battle" with the 3BB techies for a few days when my U.S. smtp sever mysteriously stopped working. Although they tried, it never become reliable as it had been for a few years. It seems they want you to use only the 3BB smtp server. Of course I could subscribe to a number of conspiracy theories as to why this is. Finally, I relented and changed to Port 2 "smtp.3bbmail.com" and I have not experienced any problems.