forced to "use default server" 2 send email. Prb start 6/30/16. sorry, i asked this 4 firefox app! can't read - glasses! age! #. prb started after install of 45.2.0. on 6/30/16. prb started on 7/1/16 with new email conversations. #. was able to logon to isp and used their webmail, thus verifying email send/receive OK. #. tried setting SMTP to smtp.cox.net. sent test email. this resulted in failure to send email. err msg "Login to server smtp.cox.net failed." resulted #. changed SMTP to "use default server" under "account" option window displayed from selecting email address, & accessing "account" option. sent test email which transmitted properly. #. informed cox support of problem with 45.2.0 release channel, release date 6/30/16, and work around. #. dx prb result: #*.a. cox online webmail send/receive with no problem <=> cox servers working correctly since their change log clean #*.b. smtp.cox.email broken with release 45.2.0. use of "use default server" correcting prb <=> t.bird send ok with "use default server" but fails with "smtp.cox.net. #*.c. sending of test emails under: #**.c.i. online webmail works ok <=> cox email continues to work correctly #**.c.ii smtp.cox.email send test email failure from t.bird <=> problem c/ 45.2.0 release #**.c.iii use default server sent test email success from t.bird <=> problem c/ 45.2.0 release #.a. note: "dx" medical abbrev for "diagnosis" #*.b. note: "c/" = latin "cum" = "with," thus "c/" medical abbrev for "with." see "https://en.wiktionary.org/wiki/cum" => Etymology 1[edit] From Latin cum ‎(“with”). #*. sorry for possible unintentional meaning assumption re. "cum." -------- This is now in Thuinderbird section of the forum. (uses original link still.) I tried to tidy up formatting a bit ~j99