[AlexLa]

I think none of our customers use ISP's smtp servers to send their mailings. ISPs often set limits for their mail servers. Most of the users have websites, so they use their own smtp servers. Easymail won't hurt deliverability rates at all because it uses the same technology as MailChimp or CampaignMonitor ( including the DomainKey and DKIM ) but it's a standalone desktop application.

The main disadvantage though is that you need your PC to stay running all the time when you send a campaign.