Hi, RhondaB!
So that the Community can help you better, we will need to know where you're inserting the envelopes, and what settings you're using on your computer. That, and any other details you'd like to give will help the Community better understand your issue!
If this is a time-sensitive matter, our US-based technical support team is standing by, ready to help 24/7 via Email at http://bit.ly/EmailCanon or by phone at 1-800-OK-CANON (1-800-652-2666) weekdays between 10 AM and 10 PM ET (7 AM to 7 PM PT).
Thanks and have a great day!
