Hostopia SMTP Mail failing

[#1]

On Hostopia ccgi I'm getting an SMTP connection failure when I try to send mail using phpmailer 5.2.9 with SMTP through 'localhost' .
Debug gives:
Connection: opening to localhost:25, t=300, opt=array ()
SMTP ERROR: Failed to connect to server: php_network_getaddresses: getaddrinfo failed: Name or service not known (0)
SMTP connect() failed.
I first noticed this late last night, but the problem is still present.
Using PHP mail() (which interfaces to sendmail) works OK.
David

[#2]

Replicated and raised with Hostopia (ref: 3658284). Apologies it took so long to pick up

[#3]

Hi David, I'm assuming things are still broken today? Hostopia say they've fixed the script I have uploaded to my webspace but from what I can ascertain, they've just switched to using PHPMail rather than SMTP.

[#4]

Yes, SMTP mail still fails with exactly the same error message. I use SMTP mail with phpList and this worked fine until the last few days,
As before sending using the php mail() function continues to work.
David

[#5]

To check if it made any difference I updated PHPMailer to version 5.2.10. Sending using SMTP on localhost continues to fail, but the error string now includes a reference to a Troubleshooting page.
Connection: opening to localhost:25, timeout=300, options=array ()
SMTP ERROR: Failed to connect to server: php_network_getaddresses: getaddrinfo failed: Name or service not known (0)
SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting
After reviewing that page DNS lookups seemed a likely source of the problem. This was confirmed by replacing 'localhost' with '127.0.0.1' in my code; with that change SMTP sending works again.
Until recently 'localhost' used to work - so what has changed? This is only a guess but I suspect Hostopia DNS now supports IPv6 with IPv6 preferred.. This implies the IP returned for 'localhost' will be '::1'. I suspect the problem is that opening a socket to port 25 using that IPv6 address then fails.
David

[#6]

Nicely spotted David.
I've changed localhost to the loopback IP in my own script and it works.
I've provided Hostopia with this diagnosis and am awaiting a response from them.

[#7]

Looks to be working now David. Can you confirm?

SMTP -> FROM SERVER:220 web86c50 ESMTP Sendmail 8.14.4/8.12.6/SuSE Linux 0.6; Tue, 18 Aug 2015 12:44:01 GMT
SMTP -> FROM SERVER: 250-web86c50 Hello localhost [127.0.0.1], pleased to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-8BITMIME 250-SIZE 250-DSN 250-ETRN 250-DELIVERBY 250 HELP
SMTP -> FROM SERVER:250 2.1.0 ... Sender ok
SMTP -> FROM SERVER:250 2.1.5 ... Recipient ok
SMTP -> FROM SERVER:354 Enter mail, end with "." on a line by itself
SMTP -> FROM SERVER:250 2.0.0 t7ICi1BD021074 Message accepted for delivery
SMTP -> FROM SERVER:221 2.0.0 web86c50 closing connection
Message sent! 

You were right BTW, it was a local DNS issue.

[#8]

Thanks. I can confirm that sending using 'localhost' as the SMTP host works again.
So problem fixed.
David