fixing several email delivery errors that occure after delivery from crm vtiger

I have several mail delivery errors, when i send emails through my crm vtiger. I use a plugin for email campaigns in vtiger. The reasons for the errors are different, e.g. the email address is no longer valid. There are about 3300 email addresses in the crm. The job is to do all steps to avoid or minimize further delivery problems, e.g. control email addresses, control entries in spam-tools like spamhouse.... here are some examples of delivery errors: ____________________________________________________________ [login to view URL]@[login to view URL]: SMTP error from remote server for RCPT TO command, host: [login to view URL] ([login to view URL]) reason: 550 5.7.1 <[login to view URL]@[login to view URL]>: Recipient address rejected: Mail appear ed to be SPAM or forged. Ask your Mail/DNS-Administrator to correct HE LO and DNS MX settings or to get removed from DNSBLs; please relay via your ISP ([login to view URL]) ____________________________________________________________ The mail system <y383122@[login to view URL]>: host [login to view URL][[login to view URL]] said: 454 4.7.1 <y383122@[login to view URL]>: Relay access denied (in reply to RCPT TO command) ____________________________________________________________ The mail system <martl3000@[login to view URL]>: host [login to view URL][[login to view URL]] said: 421 4.7.0 [TSS04] Messages from [login to view URL] temporarily deferred due to user complaints - 4.16.55.1; see [login to view URL] (in reply to MAIL FROM command) ____________________________________________________________ <www.aon.913265012@[login to view URL]>: [login to view URL] does not like recipient. track-id=1556877657:3496:smarthub83:[login to view URL] Remote host said: 554 mailbox not found Giving up on 195.3.96.71. SSL=YES ____________________________________________________________