At this time the limit on the maximum amount of mail that can be send via the mailservice, is 1000 each VPS each day. The total maximum is 10000 emails a day for which you would require a minimum of 10 VPS's in your TransIP account.
Should you require more than 10000 mails a day or possess a smaller amount of VPS's, the use of our mailservice is not yet ideal. In that case you will still need to mail directly from your VPS or use another mailprovider.
These limits are currently active to make sure all the outgoing traffic does not exceed critical levels, but after the initial startup we will evaluate if it's possible to offer (paid) expansions to this maximum amount of mails.