I've been using Pegasus Mail since they started charging to use Eudora, and the free version didn't have an address book anymore. Pegasus ran fine on my Windows 10 machine. When I got a new computer (Windows 11) I copied all the files over to the same folder (PMAIL) on the same drive (E and then installed version 4.8 as an update. It downloads mail fine but won't sent mail.

Every time I try to send mail I get this message:

Delivery has failed on the enclosed message for the following
reasons reported either by the mail delivery system on the mail
relay host or by the local TCP/IP transport module:

554 5.7.1 <c-67-162-95-76.hsd1.in.comcast.net[67.162.95.76]>: Client host rejected: Access denied

I checked all the SMTP settings and they were all OK. I then did another update install. Still wouldn't download mail. I went on the email website and sent an email to myself and I got it. I thought it might have been a problem with the email server but it's still doing it after five days so I know the problem is with Pegasus. I don't know what else to do.

Could you please help me?
Thank you,
GW Lee

Couple things I would check.
First thing I would do. Tools / Internet Options and check create Internet Session Log.
Then try and send message.
In mail directory, will create a TCPLogs directory.
Should be a pop3 and smtp log file, might have more complete messages about issue.

Second are you connect to port 25 for sending mail, or one of the secure ports.
Many ISPs have blocked access on Port 25 if not on one of their direct IP blocks, so if you are using a VPN setup, it might see you as a non-local user. Also, make sure the name is of smtp server is correct. Many ISPs use the same machine for both, but my ISP uses different names.
mail.guam.net is the pop3 server, and smtp1.guam.net is the smtp server.
Using port 995 for pop3 and 465 for smtp in my setup.

Sening mail to a local email would not require a relay, so that would work.
Think log might show more clearly what issue is.

Thanks msetzerii

This is the TCPLogs file I got after sending an email:

08:21:47.398: --- 16 Jun 2023, 8:21:47.398 ---
08:21:47.398: Connect to 'smtp.frontier.com', timeout 15 seconds.
08:21:48.538: [] SSL/TLS session established
08:21:48.538: [] ECDHE-RSA-AES128-GCM-SHA256, TLSv1.2, Kx=ECDH, Au=RSA, Enc=AESGCM(12, Mac=AEAD<lf>
08:21:48.538: [] Peer's certificate name is '/C=US/ST=New York/L=Rochester/O=Frontier Communications/CN=.frontier.com'.
08:21:48.694: >> 220 relay04.dlls.pa.frontiernet.net ESMTP Postfix<cr><lf>
08:21:48.694: << EHLO [67.162.95.76]<cr><lf>
08:21:48.726: >> 250-relay04.dlls.pa.frontiernet.net<cr><lf>
08:21:48.741: >> 250-PIPELINING<cr><lf>
08:21:48.741: >> 250-SIZE 36350634<cr><lf>
08:21:48.741: >> 250-ETRN<cr><lf>
08:21:48.741: >> 250-AUTH PLAIN LOGIN<cr><lf>
08:21:48.741: >> 250-AUTH=PLAIN LOGIN<cr><lf>
08:21:48.741: >> 250-ENHANCEDSTATUSCODES<cr><lf>
08:21:48.741: >> 250-8BITMIME<cr><lf>
08:21:48.741: >> 250-DSN<cr><lf>
08:21:48.741: >> 250-SMTPUTF8<cr><lf>
08:21:48.741: >> 250 CHUNKING<cr><lf>
08:21:48.741: << AUTH LOGIN<cr><lf>
08:21:48.773: >> 334 VXNlcm5hbWU6<cr><lf>
08:21:48.788: << Z3dsZWVAZnJvbnRpZXIuY29t<cr><lf>
08:21:48.819: >> 334 UGFzc3dvcmQ6<cr><lf>
08:21:48.819: << R29yZG9uTGVlIzE5NTc=<cr><lf>
08:21:48.866: >> 235 2.7.0 Authentication successful<cr><lf>
08:21:48.866: << MAIL FROM:gwlee@frontier.com SIZE=397<cr><lf>
08:21:48.913: >> 250 2.1.0 Ok<cr><lf>
08:21:48.913: << RCPT TO:gwlee@frontier.com<cr><lf>
08:21:48.944: >> 554 5.7.1 <c-67-162-95-76.hsd1.in.comcast.net[67.162.95.76]>: Client host rejected: Access denied<cr><lf>
08:21:48.960: << QUIT<cr><lf>
08:21:48.991: >> 221 2.0.0 Bye<cr><lf>
08:21:49.007: [!] Warning [Benign]: SSL connection improperly closed by remote host.
08:21:49.007: --- Connection closed at 16 Jun 2023, 8:21:49.007. ---
08:21:49.007:

Does this help? It doesn't mean anything to me,
gwlee

Oh man. You just posted your username and password. They are encrypted, but in easily decoded base64. Change your password!

Regarding the error, I see that you are connection to a comcast server but sending with a frontier.com address. Has that worked in the past? I seem to recall that comcast expects the sending email address to be one of their domains. Perhaps frontier.com is. If not, that could be the cause of the rejection because authentication to the server is successful. That is usually where a problem occurs.

I've never had this problem before. I've been with Comcast for about 10 months. It didn't happen until I connected with a new computer. I never even setup a Comcast email account. I don't see how Comcast could be doing it because the problem is occurring on the Yahoo server.

https://mxtoolbox.com/SuperTool.aspx?action=blacklist%3a67.162.95.76&run=toolpage

Shows that ip address on two black lists??
Status Problem LISTED SORBS DUHL 67.162.95.76 was listed
Status Problem LISTED Spamhaus ZEN 67.162.95.76 was listed

This entry in the log file is where I saw reference to a comcast server. After looking at it again, I suspect that the recipient was comcast address and this entry is a rejection by the recipients server.

I disconnected my new computer and reconnected the old one. Now it will not send mail either. Connecting the new computer must be what triggered the problem. After doing a search, it appears that it's an authentication problem:

https://postmaster.frontier.com/error.html
Common MTA error messages and resolution

Unauthorized mail relaying is not allowed

Error Message: 554 <e-mail address>: Relay access denied for <hostname><[IP address]>
Solution: You must authenticate your outgoing (SMTP) session.

https://forum.osticket.com/d/91966-unable-to-email-via-smtpclient-host-rejected-access-denied
ntozier
Mar 6, 2018
Edited

The mail server rejected your email from your webserver. A quick google search for the error code reveals:You are sending emails to an external domain and you get a Delivery Failure Message which says: 554. 5.7.1.
CauseSMTP Code 554. 5.7.1 is basically a rejection from the Recipient Domain. SMTP Code 554. 5.7.1 means 'Not allowed'. The address in MAIL FROM appears to have insufficient submission rights, or is invalid, or is not authorized with the authentication used; the address in a RCPT TO command is inconsistent with the permissions given to the user; the message data is rejected based on the submitting user.

It looks like your email server wont relay mail for @[deleted] domain.

Next, I downloaded and installed Thunderbird, and let it setup my email account. It has no problem sending mail. I then checked the SMTP port and the Connection Security settings. They are both the same as the Pegasus settings. There is also an Authentication method setting, which is OAuth2. I think this may be the problem. I can't find anything in Pegasus settings or help about OAuth2.

Note: Only the 4.81-pb3 has the Oauth2 for gmail.
So, if you have 4.80 it is using the older method .
The EHLO [67.162.95.76]<cr><lf> shows and IP address that is black listed on two Spam sites I mentioned earlier. I'm assuming that using the older method of authentication, it then checks the IP address being on a SPAM list, and if it is rejects it. Perhaps the setup Using the Oauth2 method assumes if it passes, don't bother to check if IP is in SPAM list??

The Oauth2 in Pegasus 4.81-pb3 is only setup for GMAIL, so perhaps Thunderbird has other support for Oauth2??

At one point, one of my ISPs mail servers IPs was on a black list, so if it got selected mail would be bounced. Informed ISP, and they quickly got IP address removed from blacklist.

Don't know if that is the IP your get from ISP, and perhaps someone in block did something that caused the hole set of IPs to be blacklisted. Some lists don't like dynamic IPs since hackers could just get a new IP address in block.

whois 67.162.95.76
[Querying whois.arin.net]
[whois.arin.net]

#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/resources/registry/whois/tou/
#
# If you see inaccuracies in the results, please report at
# https://www.arin.net/resources/registry/whois/inaccuracy_reporting/
#
# Copyright 1997-2023, American Registry for Internet Numbers, Ltd.
#

# start

NetRange: 67.160.0.0 - 67.191.255.255
CIDR: 67.160.0.0/11
NetName: COMCAST
NetHandle: NET-67-160-0-0-1
Parent: NET67 (NET-67-0-0-0-0)
NetType: Direct Allocation
OriginAS: AS7922
Organization: Comcast Cable Communications, LLC (CCCS)
RegDate: 2002-12-16
Updated: 2021-01-25
Ref: https://rdap.arin.net/registry/ip/67.160.0.0

I don't know anything about this stuff, that's why I'm here. But what are the odds of this happening within the 24 hour period that I changed computers? One in a million? The last thing I did on the old computer before I shut it down was to send two emails and they both went out as usual. The next day, less then 24 hours later, I hooked up the new computer and the first email I tried to send got the Mail Delivery Failure message.

Frontier-Yahoo has been using OAuth since 2017 and I have sent mail using Pegasus without a problem for the last six years. Here's the email they sent me, April 5, 2017:

Hi,
We noticed that you are accessing your Frontier Mail using a lower security sign-in that is sometimes used in third-party mail applications such as Outlook, IncrediMail, MacMail, Mozilla Thunderbird and others This can leave your Frontier Mail account vulnerable.

Frontier email uses the Yahoo email platform. Yahoo is in the process of moving users using less secure apps to a newer, more secure email access technology. This security technology, known as OAuth, helps prevent unauthorized access to your username and password. With OAuth, your log in credentials are encrypted and better protected from hackers.

We will be rolling out this change beginning May 1st, 2017 through May 31, 2017. You will be impacted at any time during this time period, so we encourage you to take steps outlined here no later than May 1st, 2017.

•Access your mail via frontier.yahoo.com or with a mail client that supports OAuth

•Upgrade your current mail client to a version that supports OAuth

•Visit https://security.frontier.com/ and create an app-specific password

For more information, a list of clients that support OAuth and step-by-step instructions, please see our help page: https://frontier.com/helpcenter/categories/internet/email/email-security-upgrade

Thank you for being a Frontier Mail user.

Sincerely,
Frontier Technical Support

I couldn't access this page, they must have taken it down. I remember going there at that time but not much else except that Thunderbird was on the list.

The first time I logged into my Amazon account with the new computer I got an email that said someone logged into your account. If it wasn't you let us know. Probably because I was using a different computer then I'd been using for the last 6 years. It then happened again after I logged into my Frontier email webpage to send an email. I think that might be what happened with my Pegasus Mail. Maybe they just let OAuth slide until I tried to log in with a different computer. They just didn't bother to send me an email to let me know.

This does not appear to be the case. The log you posted shows that authentication was successful. That would not have happened if they were requiring OAuth authentication. That log shows that the message was rejected by the receiving comcast.net server. Have you compared the log file that you posted to other log files?

OK, I can't use Pegasus to send email until my one year agreement with Comcast expires. I tried twice to get Comcast to do something about it but no one there can figure out how to fix it. The first time I got cut off after they put me on hold. (I wasn't getting anywhere anyhow.) The second time they told me to call Yahoo. They gave me a phone number but it doesn't work. I tried a third time and waited 45 minutes and hung-up. I can't find a way to contact Yahoo without purchasing a subscription and I don't have an account with Frontier, so they won't help me.

I then set-up my MSN email account (which I hardly ever use - its just back-up) on Pegasus. I can receive email but can't send email with it either. I got a 'Mail Delivery Failure':

Delivery has failed on the enclosed message for the following
reasons reported either by the mail delivery system on the mail
relay host or by the local TCP/IP transport module:

334 535 5.7.3 Authentication unsuccessful [CH0PR03CA0031.namprd03.prod.outlook.com 2023-06-27T23:14:21.445Z 08DB76E8CFF5CD44]

This is from the log:

19:14:17.025: [*] SSL/TLS session established
19:14:17.040: >> 250-AUTH LOGIN XOAUTH2<cr><lf>
19:14:22.093: >> 535 5.7.3 Authentication unsuccessful

Do you know of any email provider that does not require authentication?

You won't find one. The crux of the problem is attempts to make email more secure and minimize abuse by hardening authentication requirements. OAuth 2.0 is what we are battling now. Microsoft now requires it which explains why authentication to MSN is failing. Gmail is pushing it but still accepts authentication with an app password. Last I knew, Yahoo still accepted an app password.

Are you unable to login to your email account via a web interface and dig into the authentication options (ie: Security settings or change password options) to figure out exactly what your options are (ideally finding an option to create an app password)?

As for email providers that work with Pegasus Mail, any provider not requiring OAuth authentication will still work. Gmail does, either with an app password or by using Pegasus Mail v4.81 beta which supports Gmail OAuth2. GMX and Zoho work with basic authentication.