Email Error 551 is an SMTP error commonly seen in MailEnable servers, and is seen in two forms:
551 Sender address is not valid for your login
551 This mail server requires authentication before sending mail from a locally hosted domain
As an outsourced technical support provider for Shared Web Hosting Companies, we often encounter application errors and system faults. In the past couple of months, an error that’s often reported by cPanel/WHM users is:
Aug 17 00:25:24.450  warn: Use of uninitialized value in concatenation (.) or string at /usr/local/cpanel/3rdparty/perl/522/lib64/perl5/cpanel_lib/Mail/SpamAssassin/PerMsgStatus.pm line 3082.
Isn’t shared hosting dead already? In hosting conferences and forums this is a question we’ve heard all too often. But despite all the dire predictions in the past one decade, shared hosting is still alive and flourishing.
Every web host on earth has a shared hosting plan, and all website owners start hosting with a shared space. It is a market that just cannot be ignored, and it is still the most competitive market.
What does it take to succeed in this market? There are companies which keep growing year after year, and there are companies which stop growing after they get about 10 servers. Here is a quick overview on what the winners do right, and thus ensure their brand keeps attracting new customers.