As a side note, I’m not a fan of auto-archiving because retrieving archived emails is a damn slow process. Now that’s a lot, especially since Outlook is notoriously slow when dealing with very large mailbox files.
I don’t know if it’s a lot or not, but a simple calculation says that my PST file will grow over 3,2 Gb in 1 year. Two months later, my Outlook PST file size was 541 Mb. I use to receive around 100 emails per day on each email account – so there are about 400 new emails to be stored in my Outlook mailbox, each day (spam excluded). I have a server-sided anti-spam solution in place, so the vast majority of spam emails are trapped on my mail server and they never reach my local Inbox – which means my Inbox is only populated with those emails that I actually want to receive (personal/business/newsletters/notifications). My Outlook profile is set to receive messages from 4 email accounts (3 business addresses, 1 Gmail personal account). Here is the scenario: a couple of months ago, I’ve deployed a fresh (new) profile where Outlook 2010 was going to store my emails.
The plan was to see how large my mailbox file will get without performing any kind of maintenance on it, then to attempt to reduce the mailbox size and see the difference. To put it simple, I just let my Outlook mailbox to grow ‘natural’, without deleting unwanted messages, duplicate emails or compacting my PST file. For the last couple of months I decided do a simple test related to duplicate emails and mailbox cleanup.