一切都很好，每封電子郵件都已送達。
但在過去的幾天裡，電子郵件兩次停止工作。我只重新啟動了伺服器，它又開始工作了，但我認為，這裡的某個地方是更好的解決方案。
錯誤：
Oct 11 08:39:02 vps0241 postfix/smtp[18996]: warning: 8E39925410: flush service failure
Oct 11 08:44:25 vps0241 postfix/smtp[19987]: warning: connect to mysql server 127.0.0.1: Can't connect to MySQL server on '127.0.0.1' (111)
Oct 11 08:44:25 vps0241 postfix/smtp[19987]: warning: mysql:/etc/postfix/mysql-virtual_relaydomains.cf: table lookup problem
Oct 11 08:44:25 vps0241 postfix/smtp[19987]: warning: 54534253C3: flush service failure
Oct 11 08:44:25 vps0241 postfix/smtp[19987]: warning: mysql:/etc/postfix/mysql-virtual_relaydomains.cf: table lookup problem
Oct 11 08:44:25 vps0241 postfix/smtp[19987]: warning: 1980425473: flush service failure
Oct 11 08:44:25 vps0241 postfix/smtp[19987]: warning: mysql:/etc/postfix/mysql-virtual_relaydomains.cf: table lookup problem
Oct 11 08:44:25 vps0241 postfix/smtp[19987]: warning: 876F12546A: flush service failure
Oct 11 08:44:25 vps0241 postfix/smtp[19988]: warning: connect to mysql server 127.0.0.1: Can't connect to MySQL server on '127.0.0.1' (111)
Oct 11 08:44:25 vps0241 postfix/smtp[19988]: warning: mysql:/etc/postfix/mysql-virtual_relaydomains.cf: table lookup problem
Oct 11 08:44:25 vps0241 postfix/smtp[19988]: warning: 8E39925410: flush service failure
答案1
連接到 mysql 伺服器 127.0.0.1: 無法連接到「127.0.0.1」上的 MySQL 伺服器 (111)
指出 /etc/postfix/mysql-virtual_relaydomains.cf 中指定的資料庫連線有問題