CentOS7服务器Postfix单个邮箱无法接收邮件问题求助

各位大佬好，我现在遇到一个邮件服务器的问题，折腾好久没解决，想请教下大家：

我管理着一台CentOS7的Web+邮件服务器，上面已经有不少用户邮箱，收发都正常。最近新增了一个叫TSRalert的用户，专门用来处理某类特定业务，邮箱地址是TSRalert@tropicalstormrisk.com。现在这个账号能正常发送邮件到任何地址，但完全收不到邮件——别人给这个邮箱发信时，会收到这样的报错：

Error 550.5.1.1 Recipient address rejected: User unknown in local recipient table

我实在搞不懂为啥只有这个新账号出问题，其他老账号都好好的。服务器上装了Postfix和Sendmail，我的mail.cf配置内容如下：

mail_owner = postfix

myhostname = mail.$mydomain

mydomain = tropicalstormrisk.com

myorigin = $mydomain

inet_interfaces = all

inet_protocols = all

mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain

unknown_local_recipient_reject_code = 550

mynetworks_style = host

alias_maps = hash:/etc/aliases

alias_database = hash:/etc/aliases

mail_spool_directory = /var/mail

mailbox_command = /usr/bin/procmail

debug_peer_level = 2

debugger_command =

PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin

ddd $daemon_directory/$process_name $process_id & sleep 5

sendmail_path = /usr/sbin/sendmail.postfix

newaliases_path = /usr/bin/newaliases.postfix

mailq_path = /usr/bin/mailq.postfix

setgid_group = postdrop

html_directory = no

manpage_directory = /usr/share/man

sample_directory = /usr/share/doc/postfix-2.10.1/samples

readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES

请问这个新账号是不是还有什么配置没做？麻烦各位帮忙分析下，谢谢！

备注：内容来源于stack exchange，提问作者ALEA