我已在php.ini中设置了这些变量，但邮件不会发送超过10MB的附件：
max_execution_time = 8000 ; Maximum execution time of each script, in seconds
max_input_time = 8000 ; Maximum amount of time each script may spend parsing request data
memory_limit = 800M ; Maximum amount of memory a script may consume (8MB)
post_max_size = 50M
upload_max_filesize = 50M
解决：
通过编辑/etc/postfix/main.cf并使message_size_limit变大来解决问题。另外，对于那些遇到mail（）问题的人，请尝试“tail /var/log/mail.log”查看错误。