In 21.2-b4, movemail.c uses the function re_match() (and its friends) if XEmacs is configured --with-pop. The code expects to find a prototype for this function in regex.h. But on Solaris, there is no re_match function, although the header regex.h exists. And no, it's not in regexp.h, regexpr.h, or re_comp.h either... I don't understand this code, but I suggest using only the standardized regex functions. If you insist on using re_match, then you must add a check to configure.in and disable with-pop if re_match and friends are not found. The XOPEN blurb on regex.h follows: - http://www.opengroup.org/pubs/catalog/web.htm NAME regex.h - regular-expression-matching types SYNOPSIS #include <regex.h> DESCRIPTION The <regex.h> header defines the structures and symbolic constants used by the regcomp(), regexec(), regerror() and regfree() functions. The structure type regex_t contains at least the following member: size_t re_nsub number of parenthesised subexpressions The type regoff_t is defined as a signed arithmetic type that can hold the largest value that can be stored in either a type off_t or type ssize_t. The structure type regmatch_t contains at least the following members: regoff_t rm_so byte offset from start of string to start of substring regoff_t rm_eo byte offset from start of string of the first character after the end of substring Values for the cflags parameter to the regcomp() function: REG_EXTENDED Use Extended Regular Expressions. REG_ICASE Ignore case in match. REG_NOSUB Report only success or fail in regexec(). REG_NEWLINE Change the handling of newline. Values for the eflags parameter to the regexec() function: REG_NOTBOL The circumflex character (^), when taken as a special character, will not match the beginning of string. REG_NOTEOL The dollar sign ($), when taken as a special character, will not match the end of string. The following constants are defined as error return values: REG_NOMATCH regexec() failed to match. REG_BADPAT Invalid regular expression. REG_ECOLLATE Invalid collating element referenced. REG_ECTYPE Invalid character class type referenced. REG_EESCAPE Trailing \ in pattern. REG_ESUBREG Number in \digit invalid or in error. REG_EBRACK [ ] imbalance. REG_EPAREN \( \) or ( ) imbalance. REG_EBRACE \{ \} imbalance. REG_BADBR Content of \{ \} invalid: not a number, number too large, more than two numbers, first larger than second. REG_ERANGE Invalid endpoint in range expression. REG_ESPACE Out of memory. REG_BADRPT ?, * or + not preceded by valid regular expression. REG_ENOSYS The implementation does not support the function. The following are declared as functions and may also be declared as macros. Function prototypes must be provided for use with an ISO C compiler. int regcomp(regex_t *, const char *, int); int regexec(const regex_t *, const char *, size_t, regmatch_t[], int); size_t regerror(int, const regex_t *, char *, size_t); void regfree(regex_t *); The implementation may define additional macros or constants using names beginning with REG_. APPLICATION USAGE None. FUTURE DIRECTIONS None. SEE ALSO