I have scheduled reports which sends pdf via sendemail. But After upgrading Splunk to 8.1.3 its not working, I am seeing "Invalid address" error as below
I got a non-similar but related problem:
Alert emails were not sent anymore after a major upgrade 6.6.0 => 7.2.1 (with machine transfer) => 8.1.4 => 8.2.2 (I know, we postponed our upgrade a bit too much 😉 )
So I could not know exactly which version "broke" our email sending.
But after several try and error, I figured that the "from" from email stanza in $SPLUNK_HOME$\etc\system\local\alert_actions.conf (or Send emails as field in Settings > Server settings > Email settings) was containing a string "Splunk Server B102", perfectly supported in 6.6.0, but 8.2.2 did not agree with string containing space: after replacing the string with "Splunk_Server_B202" everything was back online!
So that was a weird one... (regression from my point of view)