imap_open: connection problems

Today I wasted 2 of my 5 available work hours pissing my life against a wall of imap_open problems.

I was trying to recurse through a POP3 mailbox, to do things with some automated alert emails.

But I kept seeing “imap_open(): Couldn’t open stream” errors. No matter what combination of host name, port, protocol, mailbox I used, I couldn’t connect.

{mail.my-isp-domain.com:110/pop3}INBOX    // Doesn't work
{mail.my-isp-domain.com}    // Also doesn't work
{mail.my-isp-domain.com:110}INBOX    // Continued failure
{mail.my-isp-domain.com/pop3}INBOX    // Exasperation beginning to set in
{wtf.wee.poo/damn}   //   FUUUUUUUUUUU*******KkkKKKKKKKK

So apparently many mail servers are configured oddly (I read that some require your username to be in the form ‘user=username@domain.com’, rather than the more correcterer ‘username@domain.com’, although that didn’t help me)…

In the end, what helped in my case (I’m absolutely sure YMMV) was that, even though I don’t think I’m connecting over SSL, I had to include “/novalidate-cert” in the server specification:

{mail.my-isp-domain.com:110/pop3/novalidate-cert}   // Rocking (finally)

Annoying.

BUT the point of this post is… how I eventually stumbled on how to debug the problem.

The call to imap_open was wrapped in a try/catch block, which was ending execution of the code before I called imap_errors() to grab an array of errors relating to my imap_open() call.

What I had to do was (a) figure out that I might benefit from imap_errors(), and (b) add a call to that in the catch block that fielded the exception thrown when  imap_open failed. I added the output of  imap_errors() to the exception, and… that told me that the error stemmed from not being able to validate the server’s SSL certificate.

try
{
    $connection = imap_open( $mailbox, $this->user, $this->password);
}
catch(Exception $e)
{
    $imapErrors = implode("; ", imap_errors());
    $message = $e->getMessage() . "\n\nIMAP ERRORS: {$imapErrors}";
    throw new Exception($message);
}

I’m making no claims about how good that is as code… but it at least forced a clue into the Exception, that allowed me to fix the problem.