du -ms on the folder with all emails tells me:

2117

While GMail tells me:

You are currently using 2079 MB

Why this difference, I asked myself. Was there a difference in the way e-mail was stored? Actually I stored my e-mail very inefficiently. E-Mail is 7bits encoded — every character is 7 bits — where my FS (like virtually every other) stores each character in a 8bits. Lets calculate the actual size of email on my disk:

>>> 2117 / 8 * 7
1848

It gets even more absurd considering that the most part of that space is used by attachments in emails, which are encoded in Base64, which uses 6bits per character. At least 50% of these 2GB are attachments, thus:

>>> 2117 / 8 * 6.5
1716

Why am I using 2079MB according to GMail?

GMail wouldn’t require 2079MB for my emails, they probably compress all attachments and old mails, they won’t even come near that 2079MB. It would therefore seem logical that they would use the real size of all emails — which should at least match the 1848MB or 2117MB, but it doesn’t.

Anyone got a good guess?

Disclaimer: This isn’t in any way meant to be anti-gmail — I love gmail, everyone loves gmail! I’m just curious.

I haven’t got a place anymore to send my gmail invites so I have them spare again.

If you want a gmail invite, just mail to bas.westerbaan [curly thing] gmail.com.

Just donate them to http://isnoop.net/gmail/!

It is the second link in google when searching for gmail invites. (first is google itself)

If you want your invites to be used send your invites to them, as I did.