Bulk mail
Ah, bulk mail. In New York City, at the general post office, there is bulk mail school. You spend a morning with an ornery postal worker who walks you through the complicated world of bulk mail. It seems boring but it is worth a million bucks. Bulk mail is the enterprise that allows the zine publisher to send their zine, which may weigh 5.4 ounces, for 31¢ instead of $1.47. If you have 1000 subscribers, the post office is saving you a lot of money.
Bulk mail is only necessary if you have a subscriber base of 100 or more people. Quite honestly, bulk mail is not worth the headache unless you have subscribers.
Bulk mail is very complicated and very worth your effort. The first thing you have to do is get a bulk mail permit which costs about $85. You get this little permit number which belongs to you and your zine. I'll tell you briefly what happens, but please bear in mind that the post office has a very comprehensive manual that explains every minute detail of accessing your permit number, labeling your envelopes as well as the actual mailing process.
The permit number data goes where your stamps usually go, in the top right hand corner of your envelope. The permit number is literally 5 lines of data:

which tells our postal friends to send your zine very cheaply. Usually, you can get your permit number printed directly on your custom made envelopes. If you don't have special envelopes printed up with your logo and return address, you can create the permit number data on stickers and slap them on. We had our Bust envelopes printed at Postal Envelopes in NYC. They printed up 2000 envelopes for $167, with our Bulk Mail date on it and even the line Forward and address correction requested printed under our return address. Which means if a subscriber has moved without notifying you, they will still get the zine. It is very very important when you are doing bulk mail to have this line printed on your envelope; otherwise when the post office can't locate the addressee they just toss your precious zine in the trash (note: please check with your bulk mail office about specific service endorsements, as they not only vary with different class mail and different requests, but may change [as of the 1st of 1998, First class, Priority, & Express must read: "Address Service Requested"]. Also note, there is a fee when the mail is returned with an address correction. By printing this statement on your envelope you are making a legal, binding agreement with the post office that you will pay these fees, so be forewarned. —Darby).
Once you have your permit number all set up, your envelopes stuffed and sealed with your zine inside it, you can slap your subscriber labels on the face of the envelope and begin sorting the envelopes according to bulk mail law. Have fun, drink some beers and don't let anyone confuse you. The actual order of the bulk mail envelopes is something the post office is quite particular about. It is literally a one person job, no matter how daunting. If you are like most zine publishers, you will probably prefer to do it all by your lonesome. Crank the tunes and don't smoke any pot.

Shipping
Not all printers ship out zines to your allotted distributors which sucks because that means you have to deal with it. If you do have a printer who does the shipping, fax over you detailed list of who gets what and make sure you go over with the printer, line by line, as to who will be getting what. If shipping is a pain in the ass for you, imagine how the printer feels. Know what I mean? You don't want them fucking up, because it will be you who has to absorb the cost of their fuck up.

UPS vs. US Post
Usually, UPS is a much more reliable, faster service than the US Post Office, although probably not cheaper, when you are dealing with sending your 1000 copies of your zine to a distributor. UPS has ground service and air service. Ground usually takes up to seven business days, making it a little longer to get to its destination but it is much much cheaper and probably the way you want to go. No matter how behind schedule you are with getting your zine anywhere, it definitely does not behoove you to spend twice as much on shipping it out. Another day, week or month later than it was supposed to get there won't keep the kids from buying your zine once it arrives. So go cheaper, you will have more cash in your pocket. Keep all your receipts, so that if your zines get lost, you can track them.

Federal Express vs. Express Mail
Both of these are expensive any which way you look at it. Federal Express is worth your money when you are trying to get artwork to your printer, that you forgot to include in your package in the first place.

First Class, Second Class, Third Class, Fourth Class Mail
The postal people are so smart they set up different classes of mail. First class gets your shit there the next day, and is top dollar cost. Fourth class, also known as book rate, is the cheapest way to go, and tends to go the pony express route. It still gets there, so don't be intimidated. I often get this one cranky fart face postal worker who gives me a hard time when I ask to send Bust fourth class, but once the magic words "printed matter" slips through my lips, she invariably pouts and weighs my items at the cheap-o rate. Don't let the postal workers try to trick you into sending your zine the more expensive routes. Always ask to send your zine "the cheapest way," which in layman's terms, means Fourth class. Second and Third class, well you probably figured out by now, is less expensive than First but not as cheap as Fourth. Don't be too concerned with your potential reader not getting your zine right away if you don't send it first class. Always send your zines out Fourth Class and save yourself some pennies. (note: When sending out mags fourth class it's best to seal them up tight. The rule about printed matter states clearly that it can contain NO ADVERTISEMENTS. So if you've got ads in your zine, make it difficult for them to figure that out. If the package is covered with tape chances are they won't waste their time. But remember, the more you send at a time, the more suspicious they get. —Darby)

Foreign Mail
Canadian's have their own mail system so bulk mail postage won't apply to them Kanucks. It usually costs a few cents more sending stuff first class to Canada and you can't send stuff to Canada fourth class, either. Same goes with European mail. You just have to suck it in and send your packages either air surface (faster, more expensive) or the three week way which is less expensive but not by much.

Custom-made Envelopes
Sounds so fancy, doesn't it? Well, don't be so impressed. All this means is that you have your zines logo, name, whatever, printed in the top left corner or your envelope. They are usually quite cheap to print up, at quantities designated by the printer. Bust uses Postal Envelopes in New York and they are extremely efficient and economical.

Rubber stamps
Ok, so you don't have the money to get custom made envelopes. Get yourself a rubber stamp made with your address on it. You can get these made at any local stationary store, college book store or speciality shops that do rubber stamps. It costs less than five bucks to get a rubber stamp. And an ink pad, don't forget the ink pad. Then you can stamp your address in the top left corner so your reader knows who sent them this zine of yours. Another key rubber stamp item is to get Forward and Address Correction Requested, so that you can stamp that on the envelope too. This way, if your potential reader has moved in the time spanned between them ordering your zine and their receipt of it, it can be forwarded accordingly. (See also Bulk Mail)

Seal envelopes
If you are gonna get custom made envelopes, for heaven's sakes, ask for Seal Envelopes, so you don't have to waste time licking or sponging the envelopes yourself. You just have to rip off this adhesive tape and viola, it's self adhesive so it sticks without your saliva.

Zip codes
The post office has a directory of zip codes. It kind of looks like the phone companies phone books actually, this thick bound white papered book. This comes in handy, especially when one of your subscribers gets a gift subscription for a friend of theirs but doesn't know their zip code and doesn't include it on their order form. It's a pain in the ass, I know, but you must get the zip code yourself in this case. And you won't regret it, because when it comes to bulk mail time, you will need the zip code of every subscriber you have, since bulk mail is all about zip codes being in ascending order. It's so easy to look up a zip code, it's scary that more people don't do it. It's as easy as opening up a dictionary to find the definition of the word, Loser.