Email restrictions for outgoing mail and maximum attachment size

Email restrictions for outgoing mail and maximum attachment size

Hi,
I am interested in your mail solution, but I am confused about email restrictions for outgoing mail. In your pricing info on your website, you stated that limits for Outgoing Emails /Day are 1000 for free plan, 2000 for standard 10 GB plan and 300 for the rest. Is that calculated on per user basis? And are there any restriction for number of recipients per one mail? Is there any difference for POP or IMAP access? And lastly, what is current limit for attachment size? I found information only about limit for whole email, not just attachment.