While it might be a small issue I would hate to see any ballots go uncounted because of handling through the mail system. I recently completed voting absentee and the adhesive on the outer envelope seems to be very weak and before I could mail mine it was damn near open. I sent an email to the local elections office and it sounds like I am not the only one with this problem. They are advising that people place a piece of tape on the outer envelope.
I am not sure if all absentee ballots across the state are uniform so this might not be an issue for you. Please check with your local elections office.
For more information in Clark County you can visit:
http://www.clark.wa.gov/...
The email address is: elections@clark.wa.gov
If you live somewhere other than Clark County please visit:
http://www.secstate.wa.gov/...
For a detailed list of contact information for your county Auditor.