Colorado makes voting convenient by sending ballots to voters allowing everyone the opportunity to vote by mail. It's the U.S. Postal Service that has the job of delivering millions of ballots to those voters. Here's how big and important that job is.

In round numbers, the USPS will deliver 3.5 million mail-in ballots in Colorado. To do that, it has to meet with representatives from each of Colorado's 64 counties to review vote-by-mail performance in the most recent primary election.

The reason for knowing vote-by-mail performance is that after getting 3.5 million ballots into the mailboxes of registered voters, the Postal Service also has to process and deliver completed ballots to election officials in each county for counting.

Colorado is one of only three U.S. states that send ballots via mail to all active voters and this will be a record year for the number of ballots mailed in the state.

The ballots will be sent out three weeks before the November 6th General Election and the USPS recommends mailing completed ballots back on or before October 31 to ensure the ballot will be delivered by election day.

Ballots must be received, (not postmarked), by 7 p.m. November 6. The USPS and Colorado Secretary of State's Office offer these tips to make sure our ballot is counted.

Every ballot is mailed to the address on the voter registration file. Now is the time to check the address on file at GoVoteColorado.com and make necessary changes. You can also check the status of your returned ballot online.

Return the ballot only in the envelope provided and make sure to sign the envelope before mailing. Also, make sure you affix proper postage to the envelope. Postage rates will vary depending on the number of pages there are to the ballot.

If you don't want to figure out the actual postage, two first class or forever stamps should be more than enough for any Colorado mail-in ballot.

Mail the ballot by October 31 or drop it off at the voter service and polling centers or a 24-hour drop box. A list of those service centers and drop boxes are included in the ballot packet you receive. Note: no postage is necessary if you drop-off rather than mail the completed ballot.