----------8<-----------
substr outside of string at (eval 491) line 20, <FILE> line 1988.
Use of uninitialized value in pattern match (m//) at (eval 491) line 22,
<FILE> line 1988.
substr outside of string at (eval 491) line 20, <FILE> line 1992.
Use of uninitialized value in pattern match (m//) at (eval 491) line 22,
<FILE> line 1992.
... more similar lines
substr outside of string at (eval 492) line 20, <FILE> line 452.
Use of uninitialized value in pattern match (m//) at (eval 492) line 22,
<FILE> line 452.
substr outside of string at (eval 492) line 20, <FILE> line 465.
Use of uninitialized value in pattern match (m//) at (eval 492) line 22,
<FILE> line 465.
... again, more similar lines
---------->8-----------
I'm using daily mainlog-files. Because eximstats don't shows a concrete
filename in above error reportings I could not easily track down the
mainlog-.. file causing the error reports.