Migration from cyrus to zimbra 8.0.6

Hello,

I try to migrate my "Cyrus IMAP4 v2.2.13-Debian-2.2.13-14+lenny3 server" to "zimbra 8.0.6".
When I use the migration tool included in zimbra (IMAP SSL 993 port, with cyrus admin account), this log appears in my cyrus server:
Mar 30 13:43:19 srv cyrus/imaps[12377]: imaps TLS negotiation failed: [ip_zimbra_server]
Mar 30 13:43:19 srv cyrus/imaps[12377]: Fatal error: tls_start_servertls() failed
Mar 30 13:43:19 srv cyrus/master[11933]: process 12377 exited, status 75
Mar 30 13:43:19 srv cyrus/master[11933]: service imaps pid 12377 in BUSY state: terminated abnormally

I need help.

Thanks!