how to know the mail type SENT vs REPLY vs FORWARD

[naren]

Is there a way to know the type of mail whether its a SENT or REPLY or FORWARD mail ?

I created a global rule on "From" criteria and calling a function on "action".

Now in that function, how to know/differentiate whether its a SENT or REPLY or FORWARD mail ?

(or) Is there any other approach to know the mail type on email SENT.

(or) is there any way to create different global rules to run 3 different actions/functions on SENT or REPLY or FORWARD mail ?

Thanks.

[mattg]

An email is an email

SOME mail clients track email threads, but mail servers rarely do (if at all)
Mail clients tend to prepend 'FWD:' to the subject of forwards, and 'RE:' to the subject of Replies, but there is no guarantee that this means that a message has been forwarded or replied, and in fact I see many spam mails that start with either a FWD or a RE in an attempt to get past some spam rules

In reality, you can't tell for sure

[katip]

servers tend to add headers such as References, In-Reply-To, Thread-Index... if none of them is present, very likely it's an initially sent mail, otherwise either a forward, reply or maybe report. but as mattg suggests, for a server mail is mail, there is no 100% safe criteria for what you want to achieve. at most initial or not by checking those headers, but also that's not 100% safe IMO.