Good day to everyone. I've always considered myself an above average troubleshooter - but I have an issue that is proving impossible to figure out despite having invested more hours than I care to admit (publicly anyway). Any suggestions on which direction(s) to head in would be most appreciated.
Hardware/site specifics:
1) 3 newer HPZ2 workstations and 2 much older HPZ400 workstations
2) All workstations run Windows 10 Pro (fully patched) / run the same antivirus/malware software / are on the same switch / there is a single internet provider for site
3) All workstations are running Office 365 (latest release)
4) All users are local admins
Issue:
I can not send CDO emails from Access on the HPZ2 workstations - the HPZ400 workstations have no problem.
My troubleshooting methodology/thinking so far:
1) Not likely an ISP or site related issue because 2/5 of the workstations have no problem
2) All workstations run the same antivirus/firewall software (there's only one antivirus/firewall policy for the entire office) - but just to rule it out - I removed the antivirus/firewall software from the HPZ2's and disabled the Windows firewall - no change in issue
4) I'm using the same server and Office 365 user email credentials during testing (saved in isladogs CDO Email Tester which I'm running from a network share) to ensure no variables when testing between workstations - so it can't be an Office 365 user-specific issue
5) The error from CDO Email Tester is always the same: " Error# -2147220974 The transport lost its connection to the server".
6) cdosys.dll is the same file version (6.6.190041.746) on all workstations
7) The HPZ2's have other software running on them (UPS monitoring software, HD health monitoring software, etc.) which use the SAME smtp.office365.com server on port 25 and user email credentials I'm using for CDO testing - and they all send their respective email alerts without any problem - so again - seems unlikely to be an Office 365 user-specific issue
8) Using PowerShell from the affected HPZ2's - I can successfully send a test email using the smtp.office365.com server on port 25
9) I set up a free account at SMTP2GO.com and using the credentials for their SMTP server can successfully send using the CDO Email Tester from the HPZ2 workstations
Hardware/site specifics:
1) 3 newer HPZ2 workstations and 2 much older HPZ400 workstations
2) All workstations run Windows 10 Pro (fully patched) / run the same antivirus/malware software / are on the same switch / there is a single internet provider for site
3) All workstations are running Office 365 (latest release)
4) All users are local admins
Issue:
I can not send CDO emails from Access on the HPZ2 workstations - the HPZ400 workstations have no problem.
My troubleshooting methodology/thinking so far:
1) Not likely an ISP or site related issue because 2/5 of the workstations have no problem
2) All workstations run the same antivirus/firewall software (there's only one antivirus/firewall policy for the entire office) - but just to rule it out - I removed the antivirus/firewall software from the HPZ2's and disabled the Windows firewall - no change in issue
4) I'm using the same server and Office 365 user email credentials during testing (saved in isladogs CDO Email Tester which I'm running from a network share) to ensure no variables when testing between workstations - so it can't be an Office 365 user-specific issue
5) The error from CDO Email Tester is always the same: " Error# -2147220974 The transport lost its connection to the server".
6) cdosys.dll is the same file version (6.6.190041.746) on all workstations
7) The HPZ2's have other software running on them (UPS monitoring software, HD health monitoring software, etc.) which use the SAME smtp.office365.com server on port 25 and user email credentials I'm using for CDO testing - and they all send their respective email alerts without any problem - so again - seems unlikely to be an Office 365 user-specific issue
8) Using PowerShell from the affected HPZ2's - I can successfully send a test email using the smtp.office365.com server on port 25
9) I set up a free account at SMTP2GO.com and using the credentials for their SMTP server can successfully send using the CDO Email Tester from the HPZ2 workstations