You mention 'filter' and 'forwarding' fails to send, so I'm assuming this is auto filtering on Inbox, selecting and forwarding specific emails.

Is the issue specifically and only when using a Message Filter to auto forward emails ? If you open a received email and select to 'reply' or 'forward' an email manually - does that work ok?

If you are suddenly having a problem sending in general: Microsoft has recently altered SMTP for it's mail accounts and I'm wondering if this has also effected you.

1. Your microsoft account and your hotmail/outlook/msn/live account and any other account using outlook server all need to have the same password. So all your microsoft accounts need to be using same password. Info at this link says:

• https://support.microsoft.com/en-gb/office/how-to-sign-in-to-hotmail-c378938b-c0eb-40c1-b99e-338dd9e776a8

Can't sign in to Hotmail or Outlook.com? Notes: Your Hotmail or Outlook.com password is the same as your Microsoft Account password.

You must logon to the webmail account via browser to sort it out. Once all your accounts/email addresses are using same password.....

2. In microsoft account accessed via a browser If you have more email addresses or hotmail addresses etc , microsoft now regard one is 'primary' and all others are alias to the account. This is not a problem when it comes to receiving mail, but can be an issue when you want to send. When it comes to 'sending' - that is smtp setting in Thunderbird - it can only send using the 'primary' email address. In webmail account, you can choose what you want to be set as 'primary', but whatever email address you set up as 'primary' - only that email address can be used for SMTP for all accounts using outlook server. So if you want to send using hotmail email address then make sure it is set up as the primary email address. But then if you have an outlook.com account as well, it will only be able to send using the hotmail primary email address. So choose the email address which you want to set up as 'primary'.

Then in Thunderbird Account Settings , all your accounts that use outlook server must have the SMTP set to use whatever you set up as primary email address.

If you have done the above and still have issue then have you contacted the authors of the Owl add-on for Microsoft Exchange?

I have no trouble manually forwarding a message. The error message only occurs when I am filtering the In-Box and then attempt to automatically forwarding the message to another E-mail address.

I have checked the "forward to" E-mail address for accuracy, and it is correct.

Is the issue Owl? Is the issue Thunderbird? Is the issue Microsoft?

See if you can rule out a few things.

Is the filter set up as the first - at the top of the list? If no, then I suggest you do it as filters get dealt with in the order listed. Does the filter have the setting to filter before or after junk classification? Suggest you use 'before'.

Do you have any Anti-Virus scanning incoming and outgoing mail? If yes, then I suggest you switch that off so that nothing is interfering with the process. You should test this for a decent amount of time to rule out any interference.

Support email: owl.support@beonex.com

I did notice someone reported an issue regarding forwarding but it was back in 2020: https://addons.thunderbird.net/en-us/thunderbird/addon/owl-for-exchange/reviews/1162487/

It's worth emailing their support to see if there has been an update on that issue.

I'm wondering if this issue has something to do with an attempt to send using SMTP which OWL does not use.

Check the Error Console to see if there's a mention of an SMTP attempt to send. It might explain why the auto filter fails.

Suggest:

• Tools > Developer Tools > Error Console
• Clear it by using the Bin icon then close it.
• REstart Thundrebird
• When filter fails to auto forward - open the Error Console
• Post an image showing what it says. It may offer some additional info.

Todd-

I am so sorry. I am old and forgetful. It is not that Thunderbird has stopped filtering/forwarding through Owl. Thunderbird NEVER filtered/forwarded through Owl.

I forgot that I had used a workaround 6 years ago, but no longer needed it and deactivated it. I have revived the workaround. It's ugly, but serves my purpose.

Megathanx for you perseverance and assistance.

The Workaround: Copy all incoming mail to a ISP provided, non-Microsoft Exchange mailbox, and then filter and forward. This dog will hunt.