support regarding crm software vtiger

I need support with email marketing with the crm vtiger. For example I want to know what can i do to avoid that mails are landing in spam folder. Can I change the smtp server to another amazon server to improve the opening rate of my emails? I have a lot of mails that can not be delivered. I want to know exactly the reason, example: ---------------------------------------------- This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: <info@[login to view URL]> Reason: delivery retry timeout exceeded ---------------------------------------------- This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: info@[login to view URL]: SMTP error from remote server for GREETING command, host: [login to view URL] ([login to view URL]) reason: 550-IP [login to view URL] is blacklisted ([login to view URL]). Help at/Hilfe unter 550 [login to view URL]