One of the reasons we do not encourage scanning of mail is the "threats" are completely harmless. Thunderbird simply does not run the scripts that malware depends on in the mail client. So in the specific case of a phishing email then your only risk is in clicking the link and going to the web site it contains.

I would assume bit defender is scanning your web movements, so why raise a flag on something innocuous, Simply to make you think it is actually doing something is the primary reason and to reinforce your fears so you keep using their product. The anti virus/Security industry relies on consumer ignorance and the judicious use of fear mongering as their sales pitch. They really don't let the facts get in the way much at all.

In all probability the message refered to has been deleted but lingers on in the file because it has not been compacted as yet. SO you could try compacting as a method of getting rid of the useless message. (appmenu > File > compact folders)

OK thanks for comments. Can I search for that particular email from its msg number ?

Would like to remove it if I can ... or it will throw up error every time it scans ...

OK thanks for comments. Can I search for that particular email from its msg number ?

Would like to remove it if I can ... or it will throw up error every time it scans ...

no the "number" is some sort of arbitrary thing invented by your anti virus product. As I took great pains to say, the email in question is probably already deleted. Did you compact and rescan to confirm it was gone or just come back with that question? I must ask as 35 minutes does not sound like long enough to do a full rescan especially as I doubt to you the message as soon as I posted and your reply took time to type.

Yes I did compact ... and did rescan same error .. same message number, hence my question. I had done this earlier today when Infirst started seeing the issue. Had seen the comment to compact on a Google search.

I would suggest creating an exception for the Thunderbird profile in bit defender so your stored email is not scanned. Then you will not get these messages.

Or you could delete all the mail one at a time until you locate whatever it is bit defender does not like. Or manually count to the 394 oldest email and hope it counts from oldest to newest and does not skip any.

Or you could ask bit defender how to locate the individual email they have identified in the file. After all it is their message you are responding to.