Error message : "out of memory"

Hi,

Everything was going fine with MHonArc and now, I 've got the following
message when I try to run it :

Writing mail .Out of memory!
mhonarc -rcfile fennec.rc -outdir /u/f/fennec/public_html/liste/archives   
48,08s user 2,29s system 93% cpu 54,088 total

Why do I have this ? Is it my fault or my server 's fault ?
I 've just add the UMASK tag with 022...

(Then MHonArc create a lockfile that I have to erase in order to
be able to run it again...)

Thanks,


Olivier