I made the mistake of replying to a linkedin connection request with my main forwarding email and have started getting spam after years of no spam (have blocked linkedin requests now).
I have been looking at the email headers of the infrequent spam messages I get in an attempt to identify the original source, in an effort to block these domains, but I don't know if it will work because I use a forwarding email. All spam messages are sent to my forwarding address, which is forwarded to me. My question is: If I blacklist entries on my main email (not the forwarding address), will it still recognize spam that has passed through the forwarding address?
Clarification on my email accounts based on the comments: One email is strictly a forwarding address that has no POP or other capabilities, nor any settings I can change, nor a web address where I can even view emails, and it is not configured in thunderbird. All emails to that account forward to my POP/webmail account. I can log onto this latter address through a website and enter white or blacklisted entries there, which I have been doing although I don't know if it will work. However, I generally do not use the webmail and have the POP information in thunderbird.
I have not used the spam filter on the webmail as I am afraid it will frequently filter out important messages and I don't want to log in and review those. I also have not played around with any thunderbird settings for spam.