$ telnet メールサーバホスト名 25
Trying 192.168.x.x...
Connected to 192.168.x.x.
Escape character is '^]'
220 メールサーバホスト名 ESMTP Postfix
ehlo testhost
250-メールサーバホスト名
250-<以下省略>
mail from: <>
250 2.1.0 Ok
rcpt to: nothing@your.domain.here
250 2.1.5 Ok
存在しないアドレスを指定した「rcpt to: nothing@your.domain.here」に対する応答として「550 5.1.1 ~」が返ってくることを期待したものの、「250 2.1.5 Ok」という、メールアドレスが存在する場合と同じ応答となっている。
[root@xxxxxxxxxxx mysql]# ls -ltr /var/lib/mysql/binlog*
-rw-r-----. 1 mysql mysql 1076027128 Apr 11 12:15 /var/lib/mysql/binlog.000401
-rw-r-----. 1 mysql mysql 895282121 Apr 23 06:48 /var/lib/mysql/binlog.000402
-rw-r-----. 1 mysql mysql 1076428654 Apr 23 19:12 /var/lib/mysql/binlog.000403
-rw-r-----. 1 mysql mysql 596357576 Apr 24 03:25 /var/lib/mysql/binlog.000404
-rw-r-----. 1 mysql mysql 1074553571 Apr 24 22:57 /var/lib/mysql/binlog.000405
-rw-r-----. 1 mysql mysql 1075609896 Apr 26 11:28 /var/lib/mysql/binlog.000406
-rw-r-----. 1 mysql mysql 1075981972 Apr 27 18:37 /var/lib/mysql/binlog.000407
-rw-r-----. 1 mysql mysql 1075913505 Apr 28 00:47 /var/lib/mysql/binlog.000408
-rw-r-----. 1 mysql mysql 1075838660 Apr 28 05:05 /var/lib/mysql/binlog.000409
-rw-r-----. 1 mysql mysql 1075205513 Apr 28 08:48 /var/lib/mysql/binlog.000410
-rw-r-----. 1 mysql mysql 5651277 Apr 29 23:47 /var/lib/mysql/binlog.000411
-rw-r-----. 1 mysql mysql 2052256 Apr 29 23:56 /var/lib/mysql/binlog.000412
-rw-r-----. 1 mysql mysql 101787 Apr 30 00:01 /var/lib/mysql/binlog.000413
-rw-r-----. 1 mysql mysql 3171581 Apr 30 03:19 /var/lib/mysql/binlog.000414
-rw-r-----. 1 mysql mysql 1074621728 May 3 02:47 /var/lib/mysql/binlog.000415
-rw-r-----. 1 mysql mysql 1074747087 May 5 18:27 /var/lib/mysql/binlog.000416
-rw-r-----. 1 mysql mysql 1074122275 May 6 01:02 /var/lib/mysql/binlog.000417
-rw-r-----. 1 mysql mysql 1076183303 May 6 16:09 /var/lib/mysql/binlog.000418
-rw-r-----. 1 mysql mysql 1074003040 May 7 01:08 /var/lib/mysql/binlog.000419
-rw-r-----. 1 mysql mysql 320 May 7 01:08 /var/lib/mysql/binlog.index
-rw-r-----. 1 mysql mysql 286409863 May 7 16:07 /var/lib/mysql/binlog.000420
[root@xxxxxxxxxxx mysql]#
とりあえず、binlog関連の設定を「show variables like ‘binlog%’;」を実行して確認してみる
[root@xxxxxxxxxxx mysql]# mysql -u root
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 50827
Server version: 8.0.45 Source distribution
Copyright (c) 2000, 2026, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show variables like 'binlog%';
+------------------------------------------------+--------------+
| Variable_name | Value |
+------------------------------------------------+--------------+
| binlog_cache_size | 32768 |
| binlog_checksum | CRC32 |
| binlog_direct_non_transactional_updates | OFF |
| binlog_encryption | OFF |
| binlog_error_action | ABORT_SERVER |
| binlog_expire_logs_auto_purge | ON |
| binlog_expire_logs_seconds | 2592000 |
| binlog_format | ROW |
| binlog_group_commit_sync_delay | 0 |
| binlog_group_commit_sync_no_delay_count | 0 |
| binlog_gtid_simple_recovery | ON |
| binlog_max_flush_queue_time | 0 |
| binlog_order_commits | ON |
| binlog_rotate_encryption_master_key_at_startup | OFF |
| binlog_row_event_max_size | 8192 |
| binlog_row_image | FULL |
| binlog_row_metadata | MINIMAL |
| binlog_row_value_options | |
| binlog_rows_query_log_events | OFF |
| binlog_stmt_cache_size | 32768 |
| binlog_transaction_compression | OFF |
| binlog_transaction_compression_level_zstd | 3 |
| binlog_transaction_dependency_history_size | 25000 |
| binlog_transaction_dependency_tracking | COMMIT_ORDER |
+------------------------------------------------+--------------+
24 rows in set (0.00 sec)
mysql>
mysql> PURGE BINARY LOGS BEFORE '2026-05-01 00:00:00';
Query OK, 0 rows affected (0.02 sec)
mysql> show binary logs;
+---------------+------------+-----------+
| Log_name | File_size | Encrypted |
+---------------+------------+-----------+
| binlog.000415 | 1074621728 | No |
| binlog.000416 | 1074747087 | No |
| binlog.000417 | 1074122275 | No |
| binlog.000418 | 1076183303 | No |
| binlog.000419 | 1074003040 | No |
| binlog.000420 | 377894939 | No |
+---------------+------------+-----------+
6 rows in set (0.00 sec)
mysql>
ファイルは・・・削除されていますね
[root@xxxxxxxxxxx mysql]# ls -ltr /var/lib/mysql/binlog*
-rw-r-----. 1 mysql mysql 1074621728 May 3 02:47 /var/lib/mysql/binlog.000415
-rw-r-----. 1 mysql mysql 1074747087 May 5 18:27 /var/lib/mysql/binlog.000416
-rw-r-----. 1 mysql mysql 1074122275 May 6 01:02 /var/lib/mysql/binlog.000417
-rw-r-----. 1 mysql mysql 1076183303 May 6 16:09 /var/lib/mysql/binlog.000418
-rw-r-----. 1 mysql mysql 1074003040 May 7 01:08 /var/lib/mysql/binlog.000419
-rw-r-----. 1 mysql mysql 96 May 7 16:25 /var/lib/mysql/binlog.index
-rw-r-----. 1 mysql mysql 383435241 May 7 16:25 /var/lib/mysql/binlog.000420
[root@xxxxxxxxxxx mysql]#
[root@xxxxxxxxxxx ~]# ls -ltr /var/lib/mysql/bin*
-rw-r-----. 1 mysql mysql 1074747087 May 5 18:27 /var/lib/mysql/binlog.000416
-rw-r-----. 1 mysql mysql 1074122275 May 6 01:02 /var/lib/mysql/binlog.000417
-rw-r-----. 1 mysql mysql 1076183303 May 6 16:09 /var/lib/mysql/binlog.000418
-rw-r-----. 1 mysql mysql 1074003040 May 7 01:08 /var/lib/mysql/binlog.000419
-rw-r-----. 1 mysql mysql 1074323672 May 8 03:18 /var/lib/mysql/binlog.000420
-rw-r-----. 1 mysql mysql 1073965591 May 8 16:47 /var/lib/mysql/binlog.000421
-rw-r-----. 1 mysql mysql 1074897443 May 10 12:39 /var/lib/mysql/binlog.000422
-rw-r-----. 1 mysql mysql 128 May 10 12:39 /var/lib/mysql/binlog.index
-rw-r-----. 1 mysql mysql 576882057 May 11 14:17 /var/lib/mysql/binlog.000423
[root@xxxxxxxxxxx ~]#
さらに翌日確認して、間違いなく増加率が激減していることを確認した
[root@xxxxxxxxxxx ~]# ls -ltr /var/lib/mysql/bin*
-rw-r-----. 1 mysql mysql 1074747087 May 5 18:27 /var/lib/mysql/binlog.000416
-rw-r-----. 1 mysql mysql 1074122275 May 6 01:02 /var/lib/mysql/binlog.000417
-rw-r-----. 1 mysql mysql 1076183303 May 6 16:09 /var/lib/mysql/binlog.000418
-rw-r-----. 1 mysql mysql 1074003040 May 7 01:08 /var/lib/mysql/binlog.000419
-rw-r-----. 1 mysql mysql 1074323672 May 8 03:18 /var/lib/mysql/binlog.000420
-rw-r-----. 1 mysql mysql 1073965591 May 8 16:47 /var/lib/mysql/binlog.000421
-rw-r-----. 1 mysql mysql 1074897443 May 10 12:39 /var/lib/mysql/binlog.000422
-rw-r-----. 1 mysql mysql 128 May 10 12:39 /var/lib/mysql/binlog.index
-rw-r-----. 1 mysql mysql 867993952 May 12 11:46 /var/lib/mysql/binlog.000423
[root@xxxxxxxxxxx ~]#