So check to see if the attachments are not too large. Your emails might get stuck in your outbox without reaching their destination due to overly large attachments.Many factors contribute to your outlook not sending emails from the outbox. You might see queries like 'error messages' after you attempt to send a message. When messages get trapped in outlook, the messages take a lot of time during sending and might eventually return unsent. So you probably are not the only one reading this article and it likes presently. Why Do Emails Go To Outbox But Not Sending?įor many outlook users mail not sending and getting jammed in the outbox is a very common thing. Part 3: How to Repair Corrupt PST Files?.Part 2: How to Fix 'Outlook Outbox Not Sending' Error?.