Hi Bill, It might help if you can tell us how you configured your mail server settings. This is normally done in ledgersmb.conf. Please obscure any usernames and passwords in your reply.  Regards David G Sent from my Samsung Mobile on the Telstra Mobile Network -------- Original message --------From: bill Ott <billott@theotts.org> Date: 1/7/18 22:28 (GMT+08:00) To: users@lists.ledgersmb.org Subject: [ledgersmb-users] Broken mail I am currently running 1.5.12 and have been since it's release. On 25 June 2018 using the recurring transactions, invoices were mailed to ~20 tenants, all successfully sent and received (I am copied on them, so I know). Today 1 July, I successfully posted a number of checks (cash->receipts), after which I attempted to send "paid invoice emails". I received the following error message. "Proxy Error The proxy server received an invalid response from an upstream server. The proxy server could not handle the request POST /ledgersmb/is.pl. Reason: Error reading from remote server" From the access_log: 192.168.0.240 - - [01/Jul/2018:09:57:10 -0400] "POST /ledgersmb/is.pl HTTP/1.1" 502 410 "https://www.theotts.org/ledgersmb/login.pl?action=login&company=SalemStreetN" "Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:61.0) Gecko/20100101 Firefox/61.0" From the error_log: [Sun Jul 01 09:58:10.822889 2018] [proxy_http:error] [pid 1380] (70007)The timeout specified has expired: [client 192.168.0.240:56182] AH01102: error reading status line from remote server localhost:5762, referer: https://www.theotts.org/ledgersmb/login.pl?action=login&company=SalemStreetN [Sun Jul 01 09:58:10.822972 2018] [proxy:error] [pid 1380] [client 192.168.0.240:56182] AH00898: Error reading from remote server returned by /ledgersmb/is.pl, referer: https://www.theotts.org/ledgersmb/login.pl?action=login&company=SalemStreetN Current Centos OS level from uname -a: Linux wbointi7.theotts.org 3.10.0-862.3.3.el7.x86_64 #1 SMP Fri Jun 15 04:15:27 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux Between 25 June and 1 July, the server hosting ledgersmb was updated, likely being the cause of the problem, but I have not found any issues I can attribute to this failure. Any help or suggestions are appreciated. -- Regards, Bill Ott Home: 919-363-0031 Cell: 919-434-7589 Email: Mailto:billott@theotts.org Website: http://www.theotts.org Profile: http://www.linkedin.com/in/wbott