mailbox TESTSUITE/test-mail/userx is locked
writing to file TESTSUITE/test-mail/userx
writing data block fd=dddd size=sss timeout=0
-delivery (local) forking for child-open
-postfork: child-open
+delivery (local) forking for transport-filter
+postfork: transport-filter
fresh-exec forked for delivery (local): npppp
-delivery (local) forked for child-open: npppp
+delivery (local) forked for transport-filter: npppp
process pppp running as transport filter: fd_write=dddd fd_read=dddd
delivery (local) forking for transport filter writer
postfork: transport filter writer