I receive emails ok but get this message when I send:
11:22:09.863: >> 550 5.1.0 tjennin2@rochester.rr.com 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

This problem started late last year.

My setup looks fine.
I talked to Spectrum Support and since I can send and receive email via spectrum webmail they say its pmail problem.
The header looks like this:

X-cs: R
X-CS-Version: 1.0
From: Self tjennin2@rochester.rr.com
X-RS-ID: <Default>
X-RS-Flags: 0,0,1,1,0,0,0
X-RS-Sigset: 0
To: bb12_22@yahoo.com
Subject: Test
MIME-Version: 1.0
Content-type: text/plain; charset=ISO-8859-1
Content-transfer-encoding: 8BIT
Date: Wed, 31 Jan 2024 11:23:46 -0500

I downloaded the latest version of PMail.
Pegasus Mail for Microsoft Windows
Copyright (C) 1992-2022, David Harris, all rights reserved
Electronic mail to support@pmail.gen.nz.

WinPMail version: Version 4.80.1028, Jan 16 2022, build ID 1028
Language resources: Standard UK English resources (EN,0,LL)
Extension Manager version: 1.14
Operating mode: Standalone
User name and ID: Single-user mode, 0
Windows version: 6.2
Windows flag word: 0
WINPMAIL.EXE directory: C:\Pmail\Programs
Home mailbox location: C:\PMAIL\MAIL
New mailbox location: C:\PMAIL\MAIL
TMP environment variable: C:\Users\Thomas\AppData\Local\Temp
TEMP environment variable: C:\Users\Thomas\AppData\Local\Temp
LAN-based SMTP support: N, N, N
NetWare MHS support: N, N, N
Built-in TCP/IP support: Enabled

• WINSOCK version: WinSock 2.0
• WINSOCK path: WSOCK32.DLLCommandline: -roam -AActive -Z options: 32768PMR variable: (None)PML variable: (None)MAI variable: (None)NB variable: (None)Autofiltering folders: 1 (1 active, 0 inactive)Last new mail count: 325Message size soft limit: 0 bytesMessage size hard limit: 0 bytesAttachment size soft limit: 0 bytesAttachment size hard limit: 0 bytes

Any suggestions as to a solution of this problem?

Thanks,

Tom Jennings

That message makes it appear that you are authenticating to Spectrum ok but are doing so with a different Spectrum email account. Do you have multiple Spectrum email addresses?

In Tools > Internet options go to the Sending (SMTP) tab:
Select the SMTP host name then click Edit.
In the Security tab, are you using the "Login to SMTP server using the following details" option? If so, the Username field must contain your full email address of tjennin2@rochester.rr.com. If it doesn't and you need to change it, don't forget to enter the appropriate password.