I need some help with an odd problem. Messages sent to a gmx.com address via MercuryC are getting delivered but ones sent via MercuryE are not. I would appreciate some help understanding what is going on. I confirmed this by sending a message from Mercury (Ctrl+N) by each method.
The entries in the MercuryE connection history window for the failure are:
Connection error during handshake with 212.227.15.10.
Connection error during handshake with 212.227.17.4.
12:19:51: processing job MO0000A6
Resolved MX for 'gmx.com' to 212.227.15.10
Connecting to 212.227.15.10
Connection error.
Attempting connection to alternate, 212.227.17.4
Connection error on alternate.
The associated MercuryE log entries are:
T 20181220 121951 5c1b6ad9 Begin processing job MO0000A6 from postmaster@mydomain.com
W 20181220 121952 5c1b6ad9 Error connecting to primary server '212.227.15.10'.
W 20181220 121953 5c1b6ad9 Error connecting to alternate server '212.227.17.4'.
E 20181220 121953 5c1b6ad9 Processing of job MO0000A6 incomplete or failed.
T 20181220 121953 5c1b6ad9 Job MO0000A6 processing complete.
Edit: A subsequent test via MercuryE with session logging enabled logged this:
15:37:14.941: --- 20 Dec 2018, 15:37:14.941 ---
15:37:14.957: Connect to '212.227.17.4', timeout 400 seconds.
15:37:15.971: >> 554-gmx.net (mxgmx117) Nemesis ESMTP Service not available<cr><lf>
15:37:15.971: >> 554-No SMTP service<cr><lf>
15:37:15.971: >> 554-Bad DNS PTR resource record.<cr><lf>
15:37:15.971: >> 554 For explanation visit http://postmaster.gmx.com/en/error-messages?ip=70.62.88.210&c=rdns<cr><lf>
15:37:15.971: << EHLO mydomain.com<cr><lf>
15:37:15.987: >>
15:37:15.987: --- Connection closed normally at 20 Dec 2018, 15:37:15.987. ---
I've looked at the explanation link buts it's beyond my level of expertise. We have a dedicated IP address but it's from Spectrum Business so could very well be in a block of address recorded as dynamically allocated. I see the EHLO as mydomain.com and wonder if that is considered a fully qualified domain name. That's fixable if it needs to be; I just don't know.
Thanks for any help.