What is the port 25 for simple mail transfer protocol?

I'm trying to use SMTP on a server and the firewall rejects it. The ports numbers don't add up to the expected 25 number.

Advertisements. Like this: LikeLoading. Related. Discussion. 8 comments for What is the port 25 for simple mail transfer protocol? I assume that port 25 is the SMTP or SMTPS port? The port used for the SMTP protocol is 587. So if you want to use SMTP you have to open port 587. I guess that the problem is in the configuration of the firewall.

Yes, I had the same problem. I found the solution, and it worked for me. I had the IP address of the router, and then I took the number of the port of my server. Then I added the IP address of the server and port of the router and the number of the router and there was my domain.

You might want to try out the SMTP configuration page at the website for more detailed help. You can use an external DNS server as the local resolver to make the name lookups more reliable. Also, set your server to listen only on the internal interface (IP addresses you control). This will prevent an outside host from being able to get a TCP connection to it, while allowing the internal hosts to get it.

What is port 993 and 465?

They both do webdav.

Should the former be opened?
nate2: not by default. If it's on port 993 (assuming it has a specific username/password configured for it) then they would have to know you're using it to use webdav. I think it's something they can configure in webdav clients
It's not setup on port 993. It's just a local directory I'm trying to mount. I just wish there was a way I could mount it into /srv/ and make apache2 use that instead of /var/www
This is just my local directory. nate2: ah, so it's only your personal home folder, right? Yes, it's just a folder I created on my desktop. Like a "Downloads" folder on windows. is there a way to show what packages are installed from a PPA in apt

kamleh ppa-purge is useful. I created it using this tutorial. MonkeyDust: cheers. kamleh. ioria: thanks. Can I create a seperate login for the terminal. Like I know my name is "Bray" but that's all I use in the terminal. I need help mounting a directory on my desktop, it's currently owned by root.

Is SMTP port 587 or 465?

To find out, you could use telnet: telnet yourhost 587.

If you don't have telnet installed (it's in the openssl package, but not in the default Ubuntu installation), you can install it with apt: sudo apt-get install telnet. Then just telnet to yourhost 587. From the Ubuntu Wiki, OpenSSL Security Page: In general, use port 25 when sending mail through a mail relay. It is safe and widely supported.

Use port 465 if the mail is for internal use only. If it is for external use, use port 587.

It is possible to check if the smtp port is 587 or 546 using the following command: netstat -ant 0 121:smtp 0.0:smtp 0.