Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    Mail servers imap behind pfsense not reachable

    Scheduled Pinned Locked Moved Firewalling
    62 Posts 8 Posters 9.7k Views
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • D
      daan
      last edited by

      @johnpoz this is my capture with 143|465|587|993 as ports
      Screenshot 2020-09-25 1449523.png

      V P 2 Replies Last reply Reply Quote 0
      • johnpozJ
        johnpoz LAYER 8 Global Moderator
        last edited by johnpoz

        Do a simple sniff on 143 then..

        Then go to can you see me . org and put in 143..

        You should see this traffic. Clearly sniffing is working.. But I don't see any traffic for 143.

        To be honest, sure looks to be working to me.. Whatever issues you might be having with imap has nothing to do with pfsense. I get a connection to 143, and sure seems to be whatever server your running behind pfsense.. reports Dovecot (Debian), which is what your Poste.io server uses for imap..

        btw I see 993 there in your sniff which would be imap over tls. Maybe your client is just not using 143 when you tested which is why you didn't see on sniff.. Do can you see me . org so you know exactly what port is being sent.

        An intelligent man is sometimes forced to be drunk to spend time with his fools
        If you get confused: Listen to the Music Play
        Please don't Chat/PM me for help, unless mod related
        SG-4860 24.11 | Lab VMs 2.8, 24.11

        D 1 Reply Last reply Reply Quote 0
        • V
          viragomann @daan
          last edited by viragomann

          @daan said in Mail servers imap behind pfsense not reachable:

          this is my capture with 143|465|587|993 as ports

          Ther is obviously a communiction on 993. Possibly your client switches automatically to 993 (SSL)?

          However, the traffic may be outbound as well. You're the only one who knows the destination IP, we cannot see it.

          GertjanG D 2 Replies Last reply Reply Quote 0
          • GertjanG
            Gertjan @viragomann
            last edited by

            @viragomann said in Mail servers imap behind pfsense not reachable:

            Ther is obviously a communiction on 993. Possibly your client switches automatically to 993 (SSL)?

            Hummm : 993 was already mentioned above.
            Check if the mail server "IMAPS" is listening on port 993 on the IMAP server before you NAT that port (TCP).

            No "help me" PM's please. Use the forum, the community will thank you.
            Edit : and where are the logs ??

            D 1 Reply Last reply Reply Quote 0
            • D
              daan @johnpoz
              last edited by daan

              @johnpoz These are my client settings, the settings worked fine with my previous router.
              Screenshot 2020-09-25 151153.png

              And yes I am using poste.io

              1 Reply Last reply Reply Quote 0
              • D
                daan @viragomann
                last edited by

                @viragomann My public IP reports in inbound as well as outbound traffic on port 993

                1 Reply Last reply Reply Quote 0
                • johnpozJ
                  johnpoz LAYER 8 Global Moderator
                  last edited by

                  Well your client not set to use 143 in that setup. So why would you think you would see traffic on 143?

                  Not sure what to tell you... Pfsense only job in this is sending the traffic on to where you tell it to send it. Clearly from your sniff that is happening on 993.. So whatever issues you have with imap has nothing to do with pfsense.. Its a dumb doorman in the big picture.. It sees traffic on port X, and sends it on to where you told it to send it.. And then sends the answer back - it has nothing to do with the workings of the conversation.. Nor does it care..

                  An intelligent man is sometimes forced to be drunk to spend time with his fools
                  If you get confused: Listen to the Music Play
                  Please don't Chat/PM me for help, unless mod related
                  SG-4860 24.11 | Lab VMs 2.8, 24.11

                  D 1 Reply Last reply Reply Quote 0
                  • D
                    daan @Gertjan
                    last edited by

                    @Gertjan Yes I did I uploaded a screenshot of it
                    alt text

                    1 Reply Last reply Reply Quote 0
                    • GertjanG
                      Gertjan
                      last edited by

                      1e7b2090-74e1-4446-8e3b-ca3df2f86c2b-image.png

                      STARTTLS seems strange when using 993 as there can't be a TLS negotiation - it will be a direct SSL/TLS connection, like your 465 = SMTPS outgoing mail connection.

                      No "help me" PM's please. Use the forum, the community will thank you.
                      Edit : and where are the logs ??

                      D 1 Reply Last reply Reply Quote 0
                      • D
                        daan @johnpoz
                        last edited by

                        @johnpoz Same story when I use port 143, it does not connect.
                        Yes I know what pfsense does, but why did it work fine on my previous router and not on my pfsense router?

                        1 Reply Last reply Reply Quote 0
                        • D
                          daan @Gertjan
                          last edited by

                          @Gertjan My mail server does TLS over port 993
                          df9c81dd-cd73-48c9-928b-5ae0cd9c6053-image.png
                          (POP, HTTP and HTTPS are not forwarded)

                          1 Reply Last reply Reply Quote 0
                          • johnpozJ
                            johnpoz LAYER 8 Global Moderator
                            last edited by

                            @daan said in Mail servers imap behind pfsense not reachable:

                            Same story when I use port 143, it does not connect.

                            It does connect.. I have connected via 143..

                            connect.png

                            An intelligent man is sometimes forced to be drunk to spend time with his fools
                            If you get confused: Listen to the Music Play
                            Please don't Chat/PM me for help, unless mod related
                            SG-4860 24.11 | Lab VMs 2.8, 24.11

                            D 1 Reply Last reply Reply Quote 0
                            • V
                              viragomann
                              last edited by

                              Since we cannot see any unencryted connection attempts, I think it's a legitimate question, if there is a valid SSL certificate installed on the IMAP server.

                              D 1 Reply Last reply Reply Quote 0
                              • D
                                daan @johnpoz
                                last edited by

                                @johnpoz Wattt the hell, when I do the same it returns
                                29d7ebdc-0255-441d-a993-44ac60e67925-image.png

                                bmeeksB 1 Reply Last reply Reply Quote 0
                                • D
                                  daan @viragomann
                                  last edited by

                                  @viragomann Yes there is, I am using Let's encrypt mail certificates.

                                  V 1 Reply Last reply Reply Quote 0
                                  • V
                                    viragomann @daan
                                    last edited by

                                    @daan
                                    Let's Encrypt is no surety for validation. Possibly the update job failed.

                                    1 Reply Last reply Reply Quote 0
                                    • bmeeksB
                                      bmeeks @daan
                                      last edited by bmeeks

                                      @daan said in Mail servers imap behind pfsense not reachable:

                                      @johnpoz Wattt the hell, when I do the same it returns
                                      29d7ebdc-0255-441d-a993-44ac60e67925-image.png

                                      Is your client trying to connect from inside your LAN or outside? This could be a NAT reflection issue. Unless you have split DNS set up so that internal clients get routed straight to the mail server's internal IP and not out the WAN, then they can't connect unless you configure that ugly beast, NAT reflection.

                                      That might be why @johnpoz can connect, but you can't. He is outside of your LAN. The standard port forward setup is going to port forward only traffic coming from the Internet into your WAN connection. It won't port forward traffic coming from your LAN side. Your previous router may have automatically configured NAT reflection when you configured a port forward. pfSense does not automatically configure NAT reflection for you.

                                      Your screenshot of the email client shows that you have configured the mail server with its hostname of "mail.xxxx.xxx", so your client will ask DNS for the corresponding IP. Since I'm betting you have your MX record in DNS pointing to your WAN IP, then your internal client will try to connect to the IMAP server using your WAN's external public IP. That's where the NAT reflection would come in. Without it, that traffic does not find your internal mail host. To see if I am correct, instead of the mail server's hostname, put it's actual internal IP address in the mail client's setup and see if it works then.

                                      D 1 Reply Last reply Reply Quote 1
                                      • johnpozJ
                                        johnpoz LAYER 8 Global Moderator
                                        last edited by johnpoz

                                        ^exactly.

                                        To be honest this comes up pretty much every single day.. Which is why I suggested can you see me . org... You have to validate traffic is getting to you from the public internet.

                                        If your setting on some box on your local network, and hitting your wan IP.. Its only going to work if you have nat reflection setup, and that is actually working. depending on the protocol, and how you set it up, or where your client is exactly compared to you, same vlan or different..

                                        And its just plain an abominations to all things holy about networking in the first place.

                                        Maybe your setup worked how you were testing it before with your old router because it was doing nat reflection. Which pfsense doesn't do without you actually setting it up.

                                        If was up to me - the whole nat reflection nonsense wouldn't even be an option.. Because its a hack, always has been a hack.. And really should never be used on any sort of real network.. Its fine for billy the user and his soho router that doesn't understand dns, doesn't really understand IPs anyway... And think he should just be able to put in his ddns address into his browser and hit xyz that is running on his own freaking box, or the raspberry pie he clicked go on for some service.

                                        But if your to the point where your running something like pfsense, and working with email servers and the like.. Time to leave the hacky lets make it work for billy bob the user because he doesn't know how to actually setup a real network anyway toys away.

                                        An intelligent man is sometimes forced to be drunk to spend time with his fools
                                        If you get confused: Listen to the Music Play
                                        Please don't Chat/PM me for help, unless mod related
                                        SG-4860 24.11 | Lab VMs 2.8, 24.11

                                        1 Reply Last reply Reply Quote 0
                                        • D
                                          daan @bmeeks
                                          last edited by

                                          @bmeeks Thanks for the explanation, When I use my IP as IMAP and SMTP it can't connect either.

                                          1 Reply Last reply Reply Quote 0
                                          • johnpozJ
                                            johnpoz LAYER 8 Global Moderator
                                            last edited by johnpoz

                                            @daan said in Mail servers imap behind pfsense not reachable:

                                            When I use my IP as IMAP and SMTP it can't connect either.

                                            What IP?? Again you need to be OUTSIDE YOUR NETWORK!! If your going to do it from inside, you need to setup nat reflection. Or just use your internal IP.

                                            I can connect to your IP just fine from outside..

                                            Just tested again, and pops right in...

                                            An intelligent man is sometimes forced to be drunk to spend time with his fools
                                            If you get confused: Listen to the Music Play
                                            Please don't Chat/PM me for help, unless mod related
                                            SG-4860 24.11 | Lab VMs 2.8, 24.11

                                            1 Reply Last reply Reply Quote 0
                                            • First post
                                              Last post
                                            Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.