I run a little greeting cards web-site on VPS. It uses Postfix to send greeting cards to clients. Currently the volume is tiny, about 10-20 cards per day. There is absolutely no spam activity (at least to my knowledge) and my IP is not blacklisted in such organizations as MAPS, www.abuse.net, etc.
I noticed that there are cases when the emails are not delivered. There are 3 major types of faults:
1. User mailbox rejections
- 550 Message was not accepted -- invalid mailbox
- Recipient address rejected: User unknown in relay recipient table (in reply to RCPT TO command)
- The e-mail address you entered couldn't be found. Please check the recipient's e-mail address and try to resend the message. If the problem continues, please contact your helpdesk.
- 550-5.1.1 The email account that you tried to reach does not exist. Please try 550-5.1.1 double-checking the recipient's email address for typos or 550-5.1.1 unnecessary spaces. Learn more at 550 5.1.1 http://support.google.com/mail/bin/answer.py?answer=6596 bk8si48484441wjb.30 (in reply to RCPT TO command)
I get this for different mail servers including gmail, yahoo, mail.ru, etc. I admit that some users may make a typo but it appears that the rate is way too high, I cannot believe there so many typos can be made.
One server reports this:
host mxs.ukr.net[220.127.116.11] said: 451 http://ukr.net/mta/std3.html?my_ip (in reply to RCPT TO command)
The link goes to the page on that server where they suggest "to properly setup queue runners".
3. Unauthorised requests
host mx9.i.ua[18.104.22.168] said: 451 Unauthorised request. Try again later (in reply to RCPT TO command)
Here are my questions, applicable to my case:
- How difficult would be to fix these issues?
- Would you recommend to hire a professional IT-specialist to configure email server?
Any help is much appreciated.