Author Topic: why avast forwards smtp port 25 to 465?  (Read 4248 times)

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Offline bajopalabra

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why avast forwards smtp port 25 to 465?
« on: November 30, 2012, 09:25:05 PM »
Hi
when I do : telnet myServer 25
the mail server replies me : 421 Cannot connect to SMTP server x.x.x.x (x.x.x.x:465), connect error 10061

after a brainburning, I discovered that unchecking mailshield->scan outbound messages
I can connect to myserver port 25 again

I want that avast scans outgoing messages, but I don't want that avast forwards them to another port

How can I do it?

I'll appreciate your comments
--
Hernan

Offline DavidR

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Re: why avast forwards smtp port 25 to 465?
« Reply #1 on: November 30, 2012, 09:40:24 PM »
Are you using a secure connection or secure logon ?
If so avast detects that and switches to the secure SMTP port.

The Mail Shield is also expecting SMTP protocol to be used over the SMTP port/s and you are using telnet protocol, so that would also throw it into a bit of a look as all email ports are redirected so that the mail shield can scan them. If you are only using telnet then I don't believe avast would be able to scan that traffic (even if there wasn't an issue with the port).
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Offline bajopalabra

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Re: why avast forwards smtp port 25 to 465?
« Reply #2 on: November 30, 2012, 10:14:15 PM »
thanks David,

we have an MS based application, using CDO.Message class for send emails

when we ran the application in a specific computer, we got an error of "transport ... 465"

why 465? we didn´t know
then, we tested with telnet, and got the same error message
we realize taht the problem was not on our application, but in something in the computer

this is the reason we've tested with telnet, at a lower level

I want to keep avast scanning outgoing messages
but I need the application send them trough port 25, not 465

TIA


Offline DavidR

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Re: why avast forwards smtp port 25 to 465?
« Reply #3 on: November 30, 2012, 10:24:23 PM »
But you need to also answer the question - Are you using a secure connection or secure logon ?

Some ISPs (GoDaddy is one I believe) misuse the SMTP port 25 for secure email, avast detects that this is going to be secure and that is why it switches to the secure SMTP port 465.

What is your email program ?
If you have your email program account settings set for SSL/TLS or to use secure logon avast will detect that and change the port.

Can you confirm if your email program account settings is set for SSL/TLS or to use secure logon ?
Windows 10 Home 64bit/ Acer Aspire F15/ Intel Core i5 7200U 2.5GHz, 8GB DDR4 memory, 256GB SSD, 1TB HDD/ avast! free 21.9.2494 (build 21.9.6698.703) UI 1.0.672/ Firefox, uBlock Origin, uMatrix/ MailWasher Pro/ Avast! Mobile Security

Offline bajopalabra

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Re: why avast forwards smtp port 25 to 465?
« Reply #4 on: December 01, 2012, 12:24:04 AM »
we have a mail server (managed by other area)
specially crafted to serve other servers
trusting them only by IP and anonymous authentication

in summary, the sender ("from" field) is not validated
and the server do not force to use a secure port for incoming connections

thanks

Offline DavidR

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Re: why avast forwards smtp port 25 to 465?
« Reply #5 on: December 01, 2012, 12:36:36 AM »
Try going into the avastUI, Real-Time Shields, Expert Settings, SSL accounts and try changing the Encryption for that account to None and the Port to 25 and see if that sticks.
Windows 10 Home 64bit/ Acer Aspire F15/ Intel Core i5 7200U 2.5GHz, 8GB DDR4 memory, 256GB SSD, 1TB HDD/ avast! free 21.9.2494 (build 21.9.6698.703) UI 1.0.672/ Firefox, uBlock Origin, uMatrix/ MailWasher Pro/ Avast! Mobile Security

Offline bajopalabra

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Re: why avast forwards smtp port 25 to 465?
« Reply #6 on: December 01, 2012, 01:16:55 AM »
ok, it worked!

I had an entry for : mydomain.com -> smtp: 25
but I also had one for : "the IP of mydomain.com" -> smtp: 465

that is, you could have conflicting entries without you being aware of that

another point to highlight is that avast add an entry automatically
when a connection is succesfully established

thanks David
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Hernán

Offline DavidR

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Re: why avast forwards smtp port 25 to 465?
« Reply #7 on: December 01, 2012, 01:23:05 AM »
You're welcome, glad that you now have it resolved.
Windows 10 Home 64bit/ Acer Aspire F15/ Intel Core i5 7200U 2.5GHz, 8GB DDR4 memory, 256GB SSD, 1TB HDD/ avast! free 21.9.2494 (build 21.9.6698.703) UI 1.0.672/ Firefox, uBlock Origin, uMatrix/ MailWasher Pro/ Avast! Mobile Security