Verizon has now blocked sending on Port 25, require 587

tdehan · Post by **tdehan** » Thu Sep 10, 2009 4:23 pm

As of the 1st of Septemeber in an effort to reduce the amount of spam send from Verizon.net email accounts Verizon has blocked port 25 and now requires users to use port 587. When this happened all of my clients that have Verizon as their ISP were unable to send email from their domain email accounts hosted with me.

Is there a work around for this?

MartynK · Post by **MartynK** » Fri Sep 11, 2009 12:11 am

What do you mean, clients could not send email to domains that you host for them or your server could not forward the emails on ?

A lot of ISP's block outgoing port 25 unless it is to their own servers, especially if the connections are DSL type.

What I have done is configured my SMTP servers to also listen on port 26, that way people can reconfigure their email clients to send to me using that. Its not perfect but it does work.

tdehan · Post by **tdehan** » Fri Sep 11, 2009 12:20 am

That is what I am asking. With Verizon now blocking port 25 as of the 1st of September. My clients that have OUTLOOK or other email clients configured to send out on port 25 are no longer able to send out from their business domain email accounts hosted with me.

Where would I configure my email servers to also listen on port 587 which is the port Verizon is mandating the configure to?

MartynK · Post by **MartynK** » Fri Sep 11, 2009 3:03 am

THE SMTP connector has a entry to configure it to listen on a additional specified port.

ahmetkemal · Post by **ahmetkemal** » Sat Sep 12, 2009 11:45 am

Just activate the submission port on SMTP port configuration window. It will work. By that way, even port 25 users or 587 port users would be able to send mail.

You don't need to change smtp port. Just activate submission port, or alternate.

tdehan · Post by **tdehan** » Wed Sep 16, 2009 4:06 pm

I have indeed activated the port settings to "listen" on port 587.

Port Settings
Submission Port
Listen to alternate port 587

When I try a telnet to mail.domainname 25 it works just fine. However, if I try telnet to mail.domainname 587 it says, Could not open connection to the host, on port 587: connect failed.

However, Verizon customers are still unable to send using Outlook with their SMTP port changed to 587. Verizon is pointing the finger at my servers. However, I am at a loss of what else to configure to allow Verizon customers with email hosted by me to send on port 587.

Post by **MailEnable-Ian** » Wed Sep 16, 2009 11:49 pm

Hi,

It could be that the Windows firewall is blocking port 587 on the server. Add the exception for the port within windows firewall settings and then restart the Windows firewall service in the Windows services list.

tdehan · Post by **tdehan** » Mon Sep 21, 2009 3:07 am

That was it! Thanks

trusnock · Post by **trusnock** » Tue Sep 29, 2009 9:09 pm

A long time ago, we set our submission port to "2525", so we've got a large number of users with this setting in their Outlook. I'd love to be able to ALSO accept submission connections on 587, but I can't think of a good way to do that (without a NAT-capable firewall to translate the port for me).

Can anyone think of an idea to add 587 without losing 2525?

Thanks,
-Tom

risager · Post by **risager** » Fri Nov 25, 2011 2:02 pm

It's sound simple, but when I try to activate "Switch on message submission" then after checkbox it says (not supported by the mail server)

Does anyone know what and how to do?
It's a Windows 2008 Webserver, Plesk 10.4 installed onto it...
Have same issue with ISP in Denmark that blocking port 25, so gonna to change it for port 587
I wish someone that can help me, because I'm novice in that.
Have a nice weekend!
Soren

Post by **MailEnable-Ian** » Sun Nov 27, 2011 11:39 pm

Hi,

It's sound simple, but when I try to activate "Switch on message submission" then after checkbox it says (not supported by the mail server)
Does anyone know what and how to do?

Where do you see this check box? Are you referring to the MailEnable SMTP properties window? Here is some help on how to enable an alternative SMTP port to listen on please review the following topic within the MailEnable documentation for locating the setting you require:

http://www.mailenable.com/documentation ... bound.html

risager · Post by **risager** » Sun Dec 11, 2011 9:53 pm

MailEnable-Ian wrote:Hi,

It's sound simple, but when I try to activate "Switch on message submission" then after checkbox it says (not supported by the mail server)
Does anyone know what and how to do?
Where do you see this check box? Are you referring to the MailEnable SMTP properties window? Here is some help on how to enable an alternative SMTP port to listen on please review the following topic within the MailEnable documentation for locating the setting you require:

http://www.mailenable.com/documentation ... bound.html

No it were in Plesk panel.. It ended up that I asked Plesk support for taking care of this issue, and they did it in mailenable admin... SO from now I know it is possible in there!
but thanks for replying anyway!

Soren

Verizon has now blocked sending on Port 25, require 587

Verizon has now blocked sending on Port 25, require 587

Re: Verizon has now blocked sending on Port 25, require 587

Re: Verizon has now blocked sending on Port 25, require 587

Re: Verizon has now blocked sending on Port 25, require 587