Tot Blocking Outgoing Smtp Connections To Non Tot Smtp Servers ?

[ukrules]

I've noticed that I'm getting an increasing amount of errors when sending email via my own SMTP server which is in Europe.

This only started recently, I'm using TOT in Bangkok. It doesn't block all connections but probably 9 out of 10.

I'm using an OpenVPN server that I have in the US right now and when I use that it works perfectly every time so this problem appears to be recently introduced and something to do with TOT.

Has anyone else noticed this ? It's a pain as I don't want to use the VPN all the time. I've seen something similar on Orange broadband in the UK in the past.

Edited March 25, 2011 by ukrules

[lomatopo]

I have been using TOT and non-TOT SMTP servers for ~ 2 years, no issues here. Not sure what a TOT SMTP server is anyway? And why would an ISP block an SMTP server?

[givenall]

I use true internet and i had problem using my provider SMTPtill i started to use 587 for the Outgoing server SMTP port

[Phil Conners]

The SMTP server is the server responsible for handling your outgoing email.

Many ISP's worldwide blocks access to other SMTP servers than their own, supposedly in order to prevent the sending of spam.

It is usually easy to get around. Either use SSL/TLS or have your smtp server using a non-standard port instead of the usual port 25.

Or you could of course use VPN but that would probably be a bit of an overkill just for that.

[lomatopo]

OK, I didn't realize anyone used port 25 anymore. And just assumed everyone knows that port 25 is blocked except if that is your ISP's mail server. Given the OP's scenario, inaccessibility 1 time in 10, I'd guess that they are not using port 25, but rather port 587, and that it is not blocked.

The OP can check, open a DOS box, at the prompt type telent smtp.yourmailserver.com port #

example:

telnet smtp.gmail.com 587

if you connect, and get a 220 response, then you are not blocked

[AyG]

I suspect that TOT has changed something recently. Over the last couple of weeks I've frequently been unable to send mail from my GMX account and getting SMTP-related error messages. However, there have been no GMX service issues. However, SMTP with Hotmail continues to work fine. Whatever TOT has done appears to be white listing the well-known names and target the more obscure. Definitely looks like an ill-considered anti-spam measure. Either that or sheer incompetence (once again).

[dave111223]

I use port 26 instead of 25 which works for my SMTP accounts.

[lomatopo]

I suspect that TOT has changed something recently. Over the last couple of weeks I've frequently been unable to send mail from my GMX account and getting SMTP-related error messages. However, there have been no GMX service issues. However, SMTP with Hotmail continues to work fine. Whatever TOT has done appears to be white listing the well-known names and target the more obscure. Definitely looks like an ill-considered anti-spam measure. Either that or sheer incompetence (once again).

What port are you using for GMX?

From: http://forum.gmx.com/forum/posts/list/3638.page

Hello everyone,

If you get the message that the SMTP server cannot be reached, then it's possible that your ISP is blocking port 25 for SMTP.

Some ISPs block port 25 and only allow access through this port to their own mail servers, in order to prevent spam abuse.

What you can do instead is to use port 587 as an alternative. Simply reconfigure your email application and where it says port 25 for SMTP, change this to 587. This should work without problems.

Best regards,

Your GMX Moderator

I can telnet to mail.gmx.com on ports 465 or 587 but not on port 25, using TOT. Using True I can telnet to mail.gmx.com on port 25. Conclusion: at this moment TOT are blocking port 25, and True are not.

What port are you using for Hotmail?

From: http://techblissonline.com/hotmail-pop3-and-smtp-settings/

Find below the Hotmail POP3 and SMTP Settings information, to configure your preferred e-mail client:

POP server: pop3.live.com (Port 995)

POP SSL required? Yes

User name: Your Windows Live ID, for example [email protected]

Password: The password you usually use to sign in to Hotmail or Windows Live

SMTP server: smtp.live.com (Port 25) {Note: If port 25 has been blocked in your network or by your ISP, you can set SMTP port to 587 with TLS or SSL Encryption depending on the client in use}

Authentication required? Yes (this matches your POP username and password)

TLS/SSL required? Yes

Edited March 27, 2011 by lomatopo

[AyG]

GMX - Port 465 not working.

Hotmail - Port 587 not blocked.

Gmail - Port 465 not blocked.

This does seem to be on a host by host basis, not simply blocking certain ports.

Telnet gives a connection message, then "Connection closed by foreign host". This could indicate that GMX is having problems - though I haven't seen any reports of this - or it could mean that TOT's transparent proxy is causing the problems.

Not sure what to do next.

[lomatopo]

GMX appear to have a problem, "connection lost" when telnet-ing into port 587. Same result on TOT and TRUE (initially a connection but then "Connection to host lost"). Maybe contact them or review their forums. It seems like they have a lot of issues. With free email one should not expect too much.

Edited March 28, 2011 by lomatopo

[Phil Conners]

You can't telnet to an encrypted (SSL) port like 465, you will get a protocol error.

[lomatopo]

You can't telnet to an encrypted (SSL) port like 465, you will get a protocol error.

You can use telnet to see if your ISP is blocking ports 25, 265, 587.

telnet smtp.youremail.com 465

If your ISP is not blocking port 465 then the screen will will clear. If your ISP is blocking any of these ports you will get an error message.

Using ports 25 or 587 you should get a 220 connection.

edited to add: That GMX mail server definitely has problems, doesn't appear to be TOT related.

telnet smtp.gmail.com 587

result:

Edited March 28, 2011 by lomatopo

[AyG]

GMX appear to have a problem, "connection lost" when telnet-ing into port 587. Same result on TOT and TRUE (initially a connection but then "Connection to host lost"). Maybe contact them or review their forums. It seems like they have a lot of issues. With free email one should not expect too much.

There are two GMXs - gmx.com (the newer company, English-language based) and gmx.net (also gmx.de I believe) (the original company, German-language based). Specifically it's gmx.net that I'm having problems with - and they don't have forums or AFAIK an email support service - just an expensive 'phone support.

[lomatopo]

GMX appear to have a problem, "connection lost" when telnet-ing into port 587. Same result on TOT and TRUE (initially a connection but then "Connection to host lost"). Maybe contact them or review their forums. It seems like they have a lot of issues. With free email one should not expect too much.

There are two GMXs - gmx.com (the newer company, English-language based) and gmx.net (also gmx.de I believe) (the original company, German-language based). Specifically it's gmx.net that I'm having problems with - and they don't have forums or AFAIK an email support service - just an expensive 'phone support.

What is your smtp address? mail.gmx.net? Did you try port 587?

Can you try a different internet access method? WiFi? 3G? 2G?

Edited March 28, 2011 by lomatopo