Outlook SendUsingAccount is null when send drafted mail

c#, outlook-addin

Solution

SendUsingAccount can be null if the property was not explicitly set. In that case you can fall back to Application.Session.CurrentUser.

Problem

I'm using `MailItem.SendUsingAccount` to get address of sender. But when I try sending a draft mail, the `SendUsingAccount` become null, while `SenderEmailAddress` still has value (but not the email address, it's Exchange property). So why `SendUsingAccount` is null? And is there any alternative way to get email address of sender?

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