Outlook MailItem: How to distinguish whether mail is incoming or outgoing?
I am writing VSTO Outlook addin in C#, and I need to distinguish, whether given MailItem is incoming or outgoing (or neither, when it is for example a draft).
Is there some foolproof way to do this? Best solution I have now would be getting a list of recipients, cc's, and bcc's, loading email adresses from active accounts, and checking if those two lists intersect, but this seems quite fragile to me, and I hope that there is a better solution.
Use case: I'd like to get a relevant date for an email, which could be either ReceivedTime, or SentOn, but to know which one I should use, I beed to know whether a mail was sent or received.
Thank you for ideas :)
Answer
Came to this page because I was having same issue in VBA. Checking the parent folders is cumbersome, as a message can be held either several folders deep (and therefore you have to iterate up several folders) or the user may have changed the folder. An extreme example: the deleted items folder contains both incoming and outgoing mail items.
I have chosen a similar solution to another person (Adi Kini) above where I check the ReceivedByName (I think he chose ReceivedEntryID). The ReceivedByName property is always Null ("") for a sent message, wherever it currently lays. This method can find a sent item that has been dragged to the inbox!. It seems a fairly reliable method of checking.
It seems odd that such an apparently straightforward thing as checking whether mail is incoming or outgoing can trip us up!