If the size of your eximstats database is too large, you can do the following steps to empty it.
Login to mysql server from root.
[root@srv1 ~]# mysql
mysql> use eximstats;
Database changed
mysql> show tables;
+---------------------+
| Tables_in_eximstats |
+---------------------+
| defers |
| failures |
| sends |
| smtp |
+---------------------+
4 rows in set (0.00 sec)
mysql> delete from defers;
Query OK, 0 rows affected (0.52 sec)
mysql> delete from failures;
Query OK, 0 rows affected (0.35 sec)
mysql> delete from sends;
Query OK, 17310 rows affected (0.23 sec)
mysql> delete from smtp;
Query OK, 4678 rows affected (0.06 sec)
mysql> exit
Bye
[root@srv1 ~]#
You can also do this by deleting the above .MYD files from the location /var/lib/mysql/eximstats and restart exim service afterwards.