Submission Port shutdowns

Hello guys,

I have a serious bug with firewall rules for my email submission port: From time to time the firewall closed the incoming connection to the submission port on my mail server. This is behavior really nerves. I put an extra rule set for opening port 587 for email delivery. Is it possible the automatic security rules closing ist from time to time? But I wanna it open for reliable email communication:

config rule
option dest_port ‘587’
option src ‘lan’
option name ‘submission’
option dest ‘wan’
option target ‘ACCEPT’

best regards


Describe why you’re setting this rule !

I don’t think there’s a need to set a rule for outgoing communications. Communication from the inside out is normally not blocked by the firewall, I use the Thunderbird client outgoing IMAP 993, SMTP 465 and no rules needed to be set.

Or do you run a mail server ?

Yes, absolutely, therefore I have opened this thread because the outgoing port 587 from LAN to WAN is closing several times without any reason? This fw rule opened the port 587 but after 1 day it is closed it again just for a first aid to overcome this incident. This is an very strange behavior and is only visible on port 587, but disturbs the email communication very massive.

It takes more than writing sometimes it doesn’t work to understand your problem. We do not have a magic crystal ball :-).

Because you’re describing an isolated problem, you need to add something extra. It states that communication outside does not need to be specifically permitted !! Your statement is not accompanied by a description of exactly how the problem manifests itself.

**Changed behavior on port 587 after adding your forward rules?
** Which application “occasionally closed port” prevents outbound communication in functions.
** Is there no problem with … how is set email client communication encryption ?
** Whether the application reports any error.
** How did you verify that the port is closed from the outside (
** See if there are any error messages in the syslog.
** Have you consulted your internet provider?

I can still think of an unlikely connection. Probably bigger experts than me will ex rule her out. Just for the world.

It has to do with honneypots. The correct function of honneypot on a particular port is such that if this port starts using another process, its function (redirect 587 to 5873) will turn off.

And GRC test (Shields UP!! — System Error) in my case ???