Profile Details

Toggle Sidebar
Recent updates
  • Interesting suggestion Nick. But I think I have found an easier one, albeit one that requires a hardware change and different service here.

    I talked to Comcast Business this morning and can get a static IP, 600 Mb service (not guaranteed of course) and access to port 25 if needed. My SMTP2GO contact noted that my current Comcast dynamic IP address is blacklisted with two major services, due to ComCast's block assignment, and I can't get that lifted. He speculates that the blacklist was what might be causing ComCast, who provides the IP, to disallow a connect. Seem logical, although it does bring the chicken or the egg, or perhaps Catch 22 into the equation.

    Anyway, the ComCast gentleman is investigating whether getting emails to a static address with them will be an issue. If I move to that service, drop Lumos altogether, the net cost is almost the same, so I expect, once the mail situation is confirmed, that I will do just that. Their business max service also provides an LTE 4G automatic backup with two different cell providers, so the need for the Lumos DSL backup goes away as well.

    There will be some work involved in removing all references to the email address, but I know most, if not all of the location that I have used it either as a logon or a return email address, so once all that is changed over, I can dump Lumos without much regret. It's not the same service I moved to from Verizon more than 20 years ago.

    I do appreciate the time you've spent in trying to help me with this problem. If nothing else, I've learned a great deal and expect that this solution is going to work, and stop the outages altogether.


  • Once Lumos comes back, I will be able to retrieve that mass of emails stuck at ClearOS. But that being said, I am now married to them if I want to continue running my own email server. Comcast is the only game in town with any speed. Verizon will never bring FIOS here, neither will Segra, and according to Comcast, most of the major providers block port 25. There's got to be some solution for this, but my tiny brain is tired and I am quitting for the day. Thank you Nick.

  • The more we talk about this, the more confused I become.

    I used tcpdump on ports 25, 465 and 587 to monitor an outbound email to my ntelos/lumos address. The send went out through port 587, not 465 or 25, on my system. So the changes I made to postfix's file have routed emails to my outbound smtp provider, which is smtp2go, via that port. They are being received at smtp2go without issue. Yes, it is an outbound server that I have used for a number of years when I could not get SMTP to function on ntelos/lumos.

    However, when I look at the emails directed to my domain name,, smtp2go indicates that it is trying to route them to the correct domain address resolved by dns but the connection to my domain times out. Since you are saying that all incoming emails are routed through port 25 and comcast blocks port 25, therein lies the problem.

    I can only assume that ntelos/lumos does NOT block port 25, but since that service is still out for me, I can't confirm it until it returns. So the problem remains -- if the comcast connection times out, routing email to the backup at ClearOS, and that backup restores via port 25, how do I deal with this problem.

    I apologize for being somewhat dense, but it just doesn't make sense. Sorry to waste so much of your time and draw on your good nature.

  • Nick, ComCast blocks port 25. That is probably what you are seeing. The question is how do I route mail delivery to my iMap server through 465 or 587. Port 25 is open on my firewall, but your telnet to port 25 should never get through ComCast, and I am sure that is what you are seeing. I need to query SMTP2GO to see how they are routing, I guess. If those emails are being routed to port 25, that's probably the answer to this problem.

  • One more comment -- I looked at how emails were being handled by my outside SMTP server and found this information:
    05/22/2020 15:01:57 Delivered []
    250 2.0.0 Ok: queued as CBBD240FDA (delivered to
    05/22/2020 15:01:57 [] Connection timed out
    05/22/2020 14:59:46 Processed localhost Received by ( ->

    So my comcast address is being queried and timing out. If I could solve why this is happening, this issue would be fixed. Any ideas? Is Comcast blocking the connection?

  • One more tidbit -- using MX toolbox, I cannot verify SMTP to my domain address. It uses the command and returns a "can't connect" error. No indication in the mail log of an attempted connect. None from ClearOS backup either, for that matter. Both Cyrus and Postfix working properly. One more thing, when attempting to connect to my external SMTP provider on port 587 with TLS, I get an error. I read somewhere that STARTTLS is not supported by Postfix on 587, but I made the suggested changes in the file, and it still errors out. No encryption works fine, as does 465 with SSL.

  • I ran a port scan, and port 587 shows as open, along with 443, 465. It started at 80, so doesn't show the status of 25, but that's open as well.

  • Clear backup is what I am using. If I get rid of the Lumos account, that says it will no longer work I guess if port 25 on Comcast has to be used. My own port 25 is open. I hate to keep asking dumb questions, but will the traffic pass through to me on 25? I have to guess no, since my A address now matches the domain name, When pinged, I get the Comcast address, since I deleted the Lumos static address.

    Try, my current outfacing dynamic address for Telnet, but that port is closed on my firewall, so it should give you a fail message.

    Thank you

  • I made a comment yesterday that I don't see, so reposting. The service went out again, probably Wednesday (20th) evening. Segra was notified, rather emphatically, that afternoon, with the promised return phone call never happening. On Thursday I received notice that they were throwing the ball back to Verizon. Tech was actually here this morning (Friday), no Verizon issue. I watched him test the line back to the CO.

    However, I spent most of yesterday trying to re-route the incoming email path. I removed the A listing for my Lumos static address, and now when I ping my domain, it references my ComCast dynamic IP. Even after talking with Comcast about the problem, the incoming emails are still piling up on the backup MX server at ClearOS. Comcast blocks port 25 and says they use 995 for incoming traffic, but I think that's for their own service, not messages that pass through to a customer IP.

    Nick mentioned that if the backups were coming in, they were coming through port 25. That isn't going to be possible with Comcast. They allow encrypted traffic on port 587, but even after switch my SMTP information to use 587, it's no go. Any ideas about how to get the traffic through Comcast will be appreciated, as heaven only knows when the Segra people are going to do their job. This has been going on for two full weeks now, and I am really tired of it.

  • Gordon Howell
    Gordon Howell likes the reply for the discussion, Re: No incoming email SMTP server unreachable

    Mail delivery uses your MX record. I am seeing:So both your MX records point to is this a mail service who then forward to you? Can they be set up with multiple IP's to deliver to?

    If you are using MultiWAN, can't your Clearcenter DDNS be prioritised to your static connection then fail over to your dynamic then you just get your mail service to use your Clearcenter DDNS?