TIMEOUT doesn't always work If a shell is invoked then procmail may wait while executing a command for longer than TIMEOUT specifies. regexp matching bug Some regexps may return an incorrect value in the MATCH variable. In particular, this can happen when 'redundant' * or + operators appear on the lefthand side of the \/ token. (The current best guess is that fixing this would require moving the "beginning of match" pointer into the "per-task" regexp structure.) Incorrect usage of -lnsl and -lsocket libsocket and libnsl should be avoided if not needed as they're broken under at least one version of IRIX. If your procmail binary doesn't reliably find user's home directories, or otherwise appears to have problems accessing the passwd file, try removing -lnsl and -lsocket from the SEARCHLIBS variable in the Makefile, then recompile. No "$@" in logged abstract When passing "$@" to a command, the "Folder:" logged does not include any of arguments passed via the "$@" Custom delimiter lossage When using a custom message delimiter (like MMDF's ^A^A^A^A\n) procmail fails to escape the delimiter in incoming messages, resulting in corrupted mailboxes. Best current workaround is to put a recipe in the /etc/procmailrc file that reads something like :0 fw * ^A^A^A^A$ |perl -pe 's:\001\001\001\001$:\002\002\002\002:' The "^A"s in the condition need to be real control-A characters. Lost value on failed chdir() If the user assigns a value to MAILDIR and the chdir() fails, the previous value of the variable (but not the process's cwd) is lost and replaced with "." Control-M isn't whitespace Every so often someone copies an rcfile from a Windows box and it ends up with CRs on the end of every line. They should be treated just like spaces and tabs are. As is, the results are really confusing. Shell Expansion Shell expansion of conditions via the '$' special treats double-quotes weirdly. They should not be considered special at all there. Backslash-newline inconsistencies Backslash-newline removal is almost completely inconsistent and should be straightened out some how, but without breaking anything that's in use.