Organizational mailboxes or SMTP addresses
As most readers of my blog knows, one of the things my business does is sell custom Active Directory management software. Our customer database is very simple; we usually track a single customer contact for each one of our customers. We periodically send out notices for maintenance contracts, updates, patches, and tips. I am surprised how many e-mail addresses that worked perfectly 6 months ago will no longer work. The IT field (as well as others) is very "fluid".
I am now becoming a big advocate for organizational / role mailboxes or SMTP addresses. These are mailboxes that server a specific function and are assigned to the person that currently has that job. Here are some examples for a test company:
Notice that I made the aliases a bit harder to "dictionary spam". You can assign these SMTP addresses to the individual that does the job or you can create dedicated mailboxes or even assign these addresses to mail groups.
The important thing to think about is that for "official" communications with the company, you set up aliases that don't change when someone leaves the company. Yes, these will become the targets of sales people, but I would rather mass delete some sales oriented e-mails than to miss things such as my support contract for software is expiring.