Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Thunderbird - SMTP port 587 & encryption selected

  • 3 replies
  • 1 has this problem
  • 1 view
  • Last reply by Matt

more options

GMX.com is one email provider I use. Their official server settings document lists 587 for SMTP (either IMAP or POP) & "STARTTLS, SSL / TLS or encryption" (meaning encrypting the password and / or content with encryption software).

I had used 465 for some time. Supposedly, 587 is now the officially recommended port for SMTP. But using port 587 & SSL / TLS won't send messages (Tbird 68.5). Only selecting STARTTLS w/ 587 works for me & GMX. Some other providers also list port 465 for SMTP & choosing SSL / TLS.

I read a couple of places that if STARTTLS is selected in Tbird, if the server if it supports it, then Tbird will use TLS. But if the server doesn't support STARTTLS, Tbird may (will??) send it unencrypted. (That's what they said).

I saw dozens of articles by "reputable sources," saying 587 was the path to Nirvana & port 465 should no longer be used. I didn't see anything definitive from Thunderbird sources on the subject.

Is there any recent info on this from Thunderbird folks? Thanks.

GMX.com is one email provider I use. Their official server settings document lists 587 for SMTP (either IMAP or POP) & "STARTTLS, SSL / TLS or encryption" (meaning encrypting the password and / or content with encryption software). I had used 465 for some time. Supposedly, 587 is now the officially recommended port for SMTP. But using port 587 & SSL / TLS won't send messages (Tbird 68.5). Only selecting STARTTLS w/ 587 works for me & GMX. Some other providers also list port 465 for SMTP & choosing <strong>SSL / TLS.</strong> I read a couple of places that if STARTTLS is selected in Tbird, if the server if it supports it, then Tbird will use TLS. But if the server doesn't support STARTTLS, Tbird may (will??) send it unencrypted. (That's what they said). I saw dozens of articles by "reputable sources," saying 587 was the path to Nirvana & port 465 should no longer be used. I didn't see anything definitive from Thunderbird sources on the subject. Is there any recent info on this from Thunderbird folks? Thanks.

Modified by JoeB

All Replies (3)

more options

You have to use what gmx states otherwise it will not work.

POP Incoming (POP3)

  • Server name: pop.gmx.com
  • Port 995
  • Connection Security: SSL/TLS
  • Authentication Method: Normal Password.
  • Username = full email address

IMAP Incoming (IMAP)

  • Server name: imap.gmx.com
  • port 993
  • Connection Security: SSL/TLS
  • Authentication Method: Normal Password.
  • Username = full email address

Outgoing (SMTP)

  • server name : mail.gmx.com
  • Port: 587
  • Connection Security: STARTTLS
  • Authentication Method: Normal Password.
  • Username = full email address

re :But if the server doesn't support STARTTLS then you would be instructed by the GMX server settings or whatever server you are using...not to use it You would use: Port: 587 Connection Security: select none Authentication method: Password, transmitted insecurely

OR they would instruct you to use: Port: 465 Connection Security: SSL/TLS Authentication Method: Normal Password. Username = full email address

Yes many servers do use those setting. I have some that do use it.

I also have some smtp servers that use Port: 465 Connection Security: SSL/TLS Authentication Method: 'OAuth2'

And others that state to send via my ISP outgoing server or use an insecure method.

BUT this does not apply to GMX, so it is not relevant.

If you did have an email address that used a smtp server which did not support either SSL/TLS nor STARTTLS and insisted you sent email through a non secure means then perhaps you should consider it time to get an email address and server that is more secure.

Modified by Toad-Hall

more options

Thanks. SMTP port 587 + SSL/TLS don't work (whether because of GMX or Tbird, or both. Pick SMTP SSL/TLS security & Tbird immediately shows for port #, "Default = 465."

But if you first enter port 587, it gives no clues about security type. Port 587 & STARTTLS will work in Tbird / on GMX.

I read a few places it may not be a good idea to use STARTTLS in Tbird - depending, but didn't find Moz docs on the topic.

more options

There are also folks on the internet that will tell you vaccinations are a conspiracy, global warming is a lie and lots of other questionable things.

STARTTLS is the most secure connection setting with a mail server. It also tends to lock out snoops and anti virus programs. That has nothing to do with it being secure, it just highlights what is to good for and the limitations of the software that can not work with it.