As Sudhakar said, do test the email connectivity on all nodes to ensure the email connection. if you are testing with outlook account id, try to provide full email id for UserID in the email account. do not give short id's/names for any emailid/userid field.
if possible configure email account for gmail, do send an email using this. if successfully sent, then there is no issues/conflicts with mail jars, in this case you have to check the credentials alone.