I'm an alumna who's helping her active chapter get a newsletter going again-- and we have to contact all alumni from scratch. It is daunting. Thankfully we only have 160 members in our 20 year history, but it is daunting.
Here's what the alumni secretary and I are doing....
First-- Compile your list of alumnae-- by class if possible (which should keep them in a rough assemblance of graduation years). Contact your college/university alumni office-- which will probably have more accurate address information than your sorority's national headquarters. You can also do a search on the addresses you DO have by looking each one up on
www.whitepages.com. You won't find everyone, but it can verify some of the ones that you already have.
Next-- Does your chapter have a website? If not, make one. If so, create a section for your alumni-- include a list of people whose addresses (and whereabouts) are unknown. Make sure there is an active email address for any alumni who are web-savvy to update their information or any of the alumnae that they keep in contact with.
Also ask them to please include email addresses. You'll pick up quite a few younger alumni who happen to stumble by the website this way, and possibly some of the older ones who are net-savvy.
Make sure to include the web address in the newsletter!
Then... Mail a mini-newsletter (or the actual newsletter) out to all addresses you have verified. In the newsletter, include a list of missing members-- you might have a full page worth's for the first newsletter, but that list should decrease with help from your alumni. Perhaps title it "Missing Roses" (or whichever your sorority's official flower/jewel/etc. is). Some of your alumnae can help you piece addresses together-- as you receive the addresses, simply mail a thank you card to the alumna for her help, and send a card-- or a copy of the newsletter with a note explaining why it's late-- to the previously lost alumna.
You may also see how many of your alumni would prefer an electronic copy of the newsletter, as opposed to a hard-copy mailed one. If you can get a group of them, organize a yahoogroup for the newsletter-- it will help keep your postage costs down.
But emphasize that you do wish to keep an accurate mailing address on file for special announcements/invites/etc.
Hope this helps!
~ Melissa