Okay folks, I get a lot of queries on here about the plugin and this is fine – to be expected in fact. The vast majority of them are about emails not arriving though so I thought I’d give you all some pointers.
Subscribe2 sends email notifications when you make a new post, it sends the email to you and puts all your subscribers email addresses into the BCC header of the email.
Now, the big problem with this is that this is a trick that SPAMMERS use! And for this reason a great deal of hosting provider impose limits on out going emails. Yes they still let you send emails and yes they give you a path to sendmail, but they only ley you send so many emails per minute or hour and they restrict the number of recipients in the BCC header.
Also, Subscribe2 follows the RFC2822 standards for email header formatting, some MTAs don’t follow it as strictly and this is where other problems arise.
Given the huge variety of hosting solutions (different web servers, web platforms, mail agents, blog setups and hosting limitations) you first port of call for failed emails (total or partial) should be your hosting provider.
They have access to your web log files and they should be able to tell you where and why your emails are being blocked. Armed with this information you will most probably be able to fix the issue or at least provide me with enough information to point you in the right direction!
As a footnote, I use Subscribe2 on my main blog site for work. I am now on VPS hosting because shared hosting repeatedly failed to send emails for my site due to anti-SPAM restrictions. Now I’m on VPS it works flawlessley without any edits to the Subscribe2 code.