Using classic Outlook for Windows in business environments
Hi,
Please follow this screenshot https://drive.google.com/file/d/1c1ufsHjdKnuyOW70BdaYTsm9bKwNSq5l/view?usp=drivesdk - Configuration to be done in cPanel WHM
Explanation:
Any email with a header will increase in length every time the user replies or forwards the same mail.
When sending emails via SMTP from Outlook, these headers need to be processed properly according to the value set in cPanel EXIM. If cPanel EXIM is configured with a header size limit smaller than 2048 bytes, outgoing emails will result in an error message. The solution is to increase the header size limit, as shown in the above screenshot.
Unfortunately, hosting companies often refuse to make this change, citing reasons such as "this is not possible" or "we cannot do this on shared hosting."
To resolve this, I created my own cPanel/WHM VPS server to have full control and apply this fix.
Quick fixes if your hosting provider doesn't respond:
- Copy-paste the email content into a new email and send it. (This works for long-threaded emails with many replies.)
- Use Mozilla Thunderbird, which does not have this issue.
If your hosting provider has made the required changes and your problem is resolved, please mention the provider's name here.
Good luck!