diff -urNp inn-2.4.6-orig/innfeed/imap_connection.c inn-2.4.6/innfeed/imap_connection.c
--- inn-2.4.6-orig/innfeed/imap_connection.c	2009-05-19 16:23:27.000000000 +0200
+++ inn-2.4.6/innfeed/imap_connection.c	2009-05-19 16:25:43.000000000 +0200
@@ -2428,7 +2428,7 @@ static conn_ret imap_sendAuthStep(connec
 
     /* convert to base64 */
     saslresult = sasl_encode64(out, outlen,
-			       inbase64, outlen*2, (unsigned *) &inbase64len);
+			       inbase64, outlen*2 + 1, (unsigned *) &inbase64len);
 
     if (saslresult != SASL_OK) return RET_FAIL;