Outgoing SMTP relay is failing

wrightthisway
wrightthisway Posts: 16 Participant
edited September 2023 in Internet 2023 Archive

I have been running my own postfix mail server at home (for personal use only) for the past 20+ years. Some time back, Spectrum put all the residential IPs on a block list so indicating they were residential (overall a good move), which then required mail sent from my server to relay via Spectrum's mail system. All was working well until about a month ago (I send little mail so not sure when this stopped working), and now any mail I send is getting bounced back, the message in my email box is as follows:


Reporting-MTA: dns; mydomain.com
X-Postfix-Queue-ID: 10E00412E057
X-Postfix-Sender: rfc822; [email protected]
Arrival-Date: Sun, 11 Jun 2023 19:19:06 -0500 (CDT)

Final-Recipient: rfc822; [email protected]
Original-Recipient: rfc822;[email protected]
Action: failed
Status: 5.1.0
Remote-MTA: dns; mail.twc.com
Diagnostic-Code: smtp; 550 5.1.0 <[email protected]> sender rejected. The
    email address you are sending as must match the email address you used to
    auth. Please check your SMTP settings. AUP#Out-1500

Above domains obfuscated, this was sending an email from my home email account to my work email (not spectrum relayed). On the postfix mail server, the following line is getting logged.

Jun 11 19:19:10 localhost postfix/smtp[66382]: 10E00412E057: to=<[email protected]>,
relay=mail.twc.com[47.43.26.4]:587, delay=4.5, delays=0.1/0.03/3.4/1, dsn=5.1.0,
status=bounced (host mail.twc.com[47.43.26.4] said: 550 5.1.0 <[email protected]>
sender rejected. The email address you are sending as must match the email address you
used to auth. Please check your SMTP settings. AUP#Out-1500 (in reply to MAIL FROM
command))


So my issue here is that mail.twc.com appears to now only accept mail that is getting sent from my spectrum email address, and not from another email/domain account. The Email Server support page is totally irrelevant to this issue, https://www.spectrum.net/support/internet/mobile-email-setup

I need to find out if there is a new process or for smtp relay so that my home email domains can continue to work going forward. I opened a support ticket a week ago and am still waiting to hear something back on this, I have to assume that the chat agent just had no idea how to route this internally. I have about a dozen email accounts here for family members that are all non-functional for sending email, but all still receive just fine.

Tagged:

Best Answer

  • William_M
    William_M Posts: 942 ✅ Verified Employee Moderator
    edited June 2023 Answer ✓

    I'm sorry, maybe a user here might be able to recommend some sort of VPN/proxy or other workaround but we won't be able to provide any support for running servers with residential service. You can reach our business team at 1-855-762-1243 if you would like to discuss what they can help with.

Answers

  • HT_Greenfield
    HT_Greenfield Posts: 603 Contributor

    May i suggest that you as the operator of your own email server go back to square one and find out from the email spam blacklisting services why your IP address is getting blacklisted and eliminate the causes and the sooner you do that and the more you keep it that way the sooner your IP address will drop out of there and the more it will stay out of there because while ISP’s utilize spam mitigation services like Spamhaus and CloudMark et c., they have nothing directly to do with their own IP addresses getting blacklisted.

  • wrightthisway
    wrightthisway Posts: 16 Participant

    Excellent idea, except that as I mentioned in my opening paragraph, Spectrum has all residential IPs on a block list that is fairly common for mail providers to utilize, and if they do then they will not accept email sent from a system on the block list. There is nothing that I can do to change that. The workaround from the past was to relay email via Spectrum's SMTP relay, which would not be blocked. This is the part that has stopped functioning.

  • HT_Greenfield
    HT_Greenfield Posts: 603 Contributor
    edited June 2023

    My bad. I'm a moron but i get it now.

    Edit: With reference to your second problem, here's a similar story but regarding a business-class static IP address so i've no doubt that things are continuing to get tightened up.

    🔗https://www.linuxquestions.org/questions/linux-server-73/550-the-email-address-you-are-sending-as-must-match-the-email-address-you-used-to-auth-4175724016/

    2nd edit: i edited this after your reply without knowing you had replied. My bad.

  • wrightthisway
    wrightthisway Posts: 16 Participant
    edited June 2023

    Don't sweat it. LOL

    I have the following line in my config for relayhost: relayhost = mail.twc.com:587

    In my sasl_password file, I had this: mail.twc.com     my-spectrum-account:mypass

    Based on something I read online recently, I updated this to be mail.twc.com:587,and substituted my spectrum email/password, but that didn't make any difference, which I suspected it wouldn't based on the error.

  • deancollins
    deancollins Posts: 11 Participant

    Same issue here in Brooklyn. Exchange outbound emails have stopped working.


    Whats worse is technical support are oblivious....... i used to have smtp-server.nyc.rr.com for outbound emails and as of Friday......all outbound are now bouncing back.


    Spent an hour on the phone with technical support and they keep saying they can only escalate issues with "Spectrum emails"..... i appreciate this is an edge case but escalate it so i can get this sorted.


    All my tech friends are equally unhelpful saying.....you shouldnt run exchange and you have to use HOSTED EMAIL.....

  • wrightthisway
    wrightthisway Posts: 16 Participant

    William, I'm not actually looking for support for the server I'm runnning, I'm looking for support regarding the smtp server that Spectrum is running, huge difference. I'm going to try opening another round of tickets this week and see if I can get any traction going here.

  • andymp3
    andymp3 Posts: 13 Participant

    Not sure why these are being marked as answered William. How do we relay emails now through mail.twc.com? As far as i can tell at the moment the FROM and AUTH DO match so what's the deal?

  • William_M
    William_M Posts: 942 ✅ Verified Employee Moderator

    The limit of our support with residential email service is verifying you can login and send/receive through our webmail, and providing these server settings so you can configure a mail client like Outlook.

  • wrightthisway
    wrightthisway Posts: 16 Participant

    I understand that position, but when an ISP blocks legitimate traffic across their network, they need to assume some level of responsibility for that and work with customers so that their service works as expected. Again, my system here has been running for about 20 years with minimal problems, and most of those were when infrastructure changed on the ISP side (Roadrunner, TimeWarner Cable, Spectrum)...

    And obviously I'm not the only customer that's stuck here from looking at this thread and others here.

  • jmoutray
    jmoutray Posts: 3 Spectator

    Same boat... 20 years. Now what? All of a sudden this functionality is no longer supported. Surely they would grandfather in their faithful Charter customers if they really cared! Hope to see an option or I'll have to go elsewhere...

  • wrightthisway
    wrightthisway Posts: 16 Participant

    Sadly I did go elsewhere, to relay email at least. dnsexit.com and smtp2go.com both provide a free tier of relay service that resolved my issue. Not the preferred solution here, but at least I can send email again after a month of struggling with this issue.

  • jmoutray
    jmoutray Posts: 3 Spectator

    Mailtrap.io works for me. 1000 emails/mo. for free. I'm jumping on AT&T fiber soon as it gets here... its in the neighborhood next to me but I'm still waiting!

  • jmoutray
    jmoutray Posts: 3 Spectator

    When I get on, I will post back here if AT&T has the same restriction on relaying email from another domain.

  • tkennelly
    tkennelly Posts: 1 Newcomer
    edited July 2023

    To both @wrightthisway and @jmoutray I too have be using Spectrum as a smart host for more than a decade. I see that both of you have found solutions. I looked at these but they did not appear to be a solution since I have a dynamic domain name associated with a dynamic IP address handled by dyndns.org. I cannot add CNAME or etc.

    Do either of use have a dynamic domain name though a service like dyndns.org and you made your solutions work?

    The good news is that I get another solution to work I can leave spectrum and move to a different service that cares about their customers.

    Thanks.

  • ChadB
    ChadB Posts: 2 Spectator

    @tkennelly Do you have your own domain that you use for email addresses? If so, you should be able to add MX records (or CNAME, etc.) to your domain that point to your dynamic DNS hostname at a minimum. I'm doing this on my config, where I point to my Dynu hostname (I stopped paying Dyndns when Oracle acquired them and made the costs more than they needed to be) in my domain MX records. I then have other names defined so I can have LetEncrypt certs for my email and web servers. I suspect that the majority of us in this situation have residential service, and are thus in a dynamic IP range (which is on the blacklists), and are doing something similar to what I've described.

  • ChadB
    ChadB Posts: 2 Spectator

    @wrightthisway Thanks for pointing me in the direction of a couple of mail relay services. I settled on SMTP2Go and configured my domain's DNS based on the entries they provided, created a username/password, and punched them all into my Postfix config on my mail server, and voila, email started flowing again. A positive side effect is that I can now see how many messages get sent monthly, and also a few more details about delivery, reading, etc. which is a bit of an improvement over how things were, but I'd still have been happy to not have had to work thru this in the past 24 hours. I will say that I did this on a DHCP based Spectrum connection, so I can attest that you can make it work with systems on Dynamic DNS services, provide you have a domain you own/control.

  • wrightthisway
    wrightthisway Posts: 16 Participant

    @tkennelly, I do have dynamic DNS going here, I use both dnsexit.com and he.net to provide this, and have been using them for years. Adding CNAME is just a matter of updating the records on their system. And they provide this service at no charge, which is great. I used to only run one provider, but there was a large internet disruption a while back that took my server offline for a time, after that I added a second provider for redundancy.

This discussion has been closed.