Occasionally Odin Plesk customers report inability to send or receive emails reporting the following Outlook errors:
The host 'mail.domain.com' could not be found. Please verify that you have entered the server name correctly. Account: 'username', Server: 'mail.domain.com', Protocol: SMTP, Port: 25, Secure(SSL): No, Socket Error: 11001, Error Number: 0x800CCC0D.
Now almost every webmaster uses a mobile device to check and reply to their business mails, but the increased mobility presents an issue of mails going out of sync between the various devices they use.
Engineers in our help desk support team often receive requests to locate missing mails sent from mobile devices. This is mostly reported by iPhone and iPad users, and is caused by differing naming conventions for the “sent” mail folder in different mail clients.
SMTP error from remote mail server after RCPT TO:<firstname.lastname@example.org>:
host mx.server.com [xxx.xxx.xxx.xxx]: 550-Verification failed for <email@example.com>
550-The mail server could not deliver mail to firstname.lastname@example.org. The account ordomain may not exist, they may be blacklisted, or missing the proper dns entries.
550 Sender verify failed
If you are a Parallels Plesk web host, you would recognize this as one of the common errors reported by your customers.
Sender verify failed can be caused by issues ranging from improper file permissions to RFC non-compliance. Engineers at Bobcares help desk support services collect detailed information regarding the error through log analysis and engaging the customer. The following are the few of the common causes for this error. (more…)
The mail user reports the error:
Task email@example.com – Sending reported error (0x800CCC78): ‘Cannot send the
message. Verify the email address in your account properties. The server
responded: 550 Access denied – Invalid HELO name (See RFC2821 220.127.116.11)
Corresponding entry in Postfix logs say:
2014-09-12 12:19:45 H=isp-ip-rev-dns.net [xxx.xxx.xxx.xxx] rejected MAIL :
Access denied - Invalid HELO name (See RFC2821 18.104.22.168)
At Bobcares help desk support services, this is a common error we see in Parallels Plesk shared hosting servers. Strict anti-spam rules or lack of SMTP authentication usually cause this error. Given below are a few scenarios we’ve encountered, and the solutions we provided for them. (more…)
Are your cPanel, Plesk or DirectAdmin servers email blacklisted? Here’s how you can prevent spam block listing of web hosting servers
Spam block listing or IP address blacklisting happens when spam traps detect outbound spam mails from a web hosting server. Spam mails are primarily sent using:
1. Spam scripts uploaded to a hacked web site which has outdated and vulnerable web applications(WordPress, Joomla, Drupal, etc).
2. Stolen/leaked passwords to email accounts that allow spam mails through email authentication.
3. Un-secured email server that acts as an open email relay. (more…)
At one time or another, every shared web hosting company has had to deal with email blacklisting issues. Hacked web sites, stolen/leaked account login details, or improperly configured mail servers allow hackers to send out thousands of spam, raising red flags in IP reputation monitors across the internet.
Bobcares help desk support services has helped web hosts prevent getting listed in spam blacklists through adopting industry best practices. In this post, a brief rundown is given on the top effective solutions to prevent IP blacklisting. (more…)