Daily, if find a number of the following errors in server-out.log - the mail queue is working though.

Last week it stopped working (fixed by restarting JIRA, Flush mail queue did not help), and I had found these errors then - and had assumed them the cause - but I still find these errors now that the mail queue is working again.

– Conversion to Long, where Integer is expected.
ERROR [velocity] Left side of '>' operation is not a valid type. It is a class java.lang.Long. Currently only integers (1,2,3...) and Integer type is supported. templates/email/html/includes/summary-topleft.vm [line 75, column 74]
ERROR [velocity] Left side of '>' operation is not a valid type. It is a class java.lang.Long. Currently only integers (1,2,3...) and Integer type is supported. templates/email/html/includes/summary-topleft.vm [line 85, column 58]

– Null value, maybe object reference not valid?
ERROR [velocity] Left side ($issue.getString("description").length()) of '!=' operation has null value. Operation not possible. templates/email/html/includes/summary-bottom.vm [line 47, column 49]
ERROR [velocity] Left side ($issue.getString("environment").length()) of '!=' operation has null value. Operation not possible. templates/email/text/includes/issuesummary.vm [line 56, column 49]
ERROR [velocity] Left side ($issue.getLong("timeestimate").longValue()) of '>' operation has null value. Operation not possible. templates/email/html/includes/summary-topleft.vm [line 85, column 58]

– Null Pointer Exception.
ERROR [velocity] ASTMethod.execute() : exception from introspection : java.lang.NullPointerException