Hi,
How large was/is this email?
What email service do you use (Gmail, Outlook.com, AOL, other)?
Do you use webmail or a desktop/phone client?
Webmail sends immediately and almost instantaneously, so you must be talking about a desktop client of some sort. Even so, I don't understand how it could take several
weeks! Are you sure you're not misunderstanding what's going on? Do you mean you clicked to 'send' the email but when you checked back later it was still in your outbox? In this case, it simply might not have sent. What happens if you try resending?