[exo]

У вас запись МХ настроена неправильно. »

похоже не только MX, но и А записи...

C:\Users\user>nslookup mail.mueller-candles-ru.com ns3-l2.nic.ru in-addr.arpa nameserver = f.in-addr-servers.arpa in-addr.arpa nameserver = b.in-addr-servers.arpa in-addr.arpa nameserver = e.in-addr-servers.arpa in-addr.arpa nameserver = d.in-addr-servers.arpa in-addr.arpa nameserver = a.in-addr-servers.arpa in-addr.arpa nameserver = c.in-addr-servers.arpa a.in-addr-servers.arpa internet address = 199.212.0.73 a.in-addr-servers.arpa AAAA IPv6 address = 2001:500:13::73 b.in-addr-servers.arpa internet address = 199.253.183.183 b.in-addr-servers.arpa AAAA IPv6 address = 2001:500:87::87 c.in-addr-servers.arpa internet address = 196.216.169.10 c.in-addr-servers.arpa AAAA IPv6 address = 2001:43f8:110::10 d.in-addr-servers.arpa internet address = 200.10.60.53 d.in-addr-servers.arpa AAAA IPv6 address = 2001:13c7:7010::53 e.in-addr-servers.arpa internet address = 203.119.86.101 e.in-addr-servers.arpa AAAA IPv6 address = 2001:dd8:6::101 f.in-addr-servers.arpa internet address = 193.0.9.1 f.in-addr-servers.arpa AAAA IPv6 address = 2001:67c:e0::1 Server: UnKnown Address: 193.232.146.1 *** UnKnown can't find mail.mueller-candles-ru.com: Non-existent domain C:\Users\user>nslookup mx01.mueller-candles-ru.com ns3-l2.nic.ru in-addr.arpa nameserver = e.in-addr-servers.arpa in-addr.arpa nameserver = a.in-addr-servers.arpa in-addr.arpa nameserver = f.in-addr-servers.arpa in-addr.arpa nameserver = d.in-addr-servers.arpa in-addr.arpa nameserver = b.in-addr-servers.arpa in-addr.arpa nameserver = c.in-addr-servers.arpa a.in-addr-servers.arpa internet address = 199.212.0.73 a.in-addr-servers.arpa AAAA IPv6 address = 2001:500:13::73 b.in-addr-servers.arpa internet address = 199.253.183.183 b.in-addr-servers.arpa AAAA IPv6 address = 2001:500:87::87 c.in-addr-servers.arpa internet address = 196.216.169.10 c.in-addr-servers.arpa AAAA IPv6 address = 2001:43f8:110::10 d.in-addr-servers.arpa internet address = 200.10.60.53 d.in-addr-servers.arpa AAAA IPv6 address = 2001:13c7:7010::53 e.in-addr-servers.arpa internet address = 203.119.86.101 e.in-addr-servers.arpa AAAA IPv6 address = 2001:dd8:6::101 f.in-addr-servers.arpa internet address = 193.0.9.1 f.in-addr-servers.arpa AAAA IPv6 address = 2001:67c:e0::1 Server: UnKnown Address: 193.232.146.1 *** UnKnown can't find mx01.mueller-candles-ru.com: Non-existent domain

при этом:

C:\Users\user>nslookup mx01.mueller-candles-ru.com.mueller-candles-ru.com ns3-l2.nic.ru in-addr.arpa nameserver = a.in-addr-servers.arpa in-addr.arpa nameserver = c.in-addr-servers.arpa in-addr.arpa nameserver = b.in-addr-servers.arpa in-addr.arpa nameserver = d.in-addr-servers.arpa in-addr.arpa nameserver = f.in-addr-servers.arpa in-addr.arpa nameserver = e.in-addr-servers.arpa a.in-addr-servers.arpa internet address = 199.212.0.73 a.in-addr-servers.arpa AAAA IPv6 address = 2001:500:13::73 b.in-addr-servers.arpa internet address = 199.253.183.183 b.in-addr-servers.arpa AAAA IPv6 address = 2001:500:87::87 c.in-addr-servers.arpa internet address = 196.216.169.10 c.in-addr-servers.arpa AAAA IPv6 address = 2001:43f8:110::10 d.in-addr-servers.arpa internet address = 200.10.60.53 d.in-addr-servers.arpa AAAA IPv6 address = 2001:13c7:7010::53 e.in-addr-servers.arpa internet address = 203.119.86.101 e.in-addr-servers.arpa AAAA IPv6 address = 2001:dd8:6::101 f.in-addr-servers.arpa internet address = 193.0.9.1 f.in-addr-servers.arpa AAAA IPv6 address = 2001:67c:e0::1 Server: UnKnown Address: 193.232.146.1 Name: mx01.mueller-candles-ru.com.mueller-candles-ru.com Address: 82.140.69.250

Ripping Corpse, а PTR запись у вас есть? посмотрите ещё раз ссылку о записях для работы почты.