Manual Settings
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Mail Server Username: no-reply+domain.com
Incoming Mail Server: mail.domain.com
Incoming Mail Server: (SSL) host200.hostmonster.com
Outgoing Mail Server: mail.domain.com (server requires authentication) port 26
Outgoing Mail Server: (SSL) host200.hostmonster.com (server requires authentication) port 465
Supported Incoming Mail Protocols: POP3, POP3S (SSL/TLS), IMAP, IMAPS (SSL/TLS)
Supported Outgoing Mail Protocols: SMTP, SMTPS (SSL/TLS)

Warning: Changing MX to something besides domain.com will prevent us from managing your mail. The email will no longer be sent to this server.

Increase RAM size
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Some time there is problem with kernel.. as rams physically is 8GB. The reason for 3GB RAM is kernel not updated, so the high volume memory is not recognized. Try this command to update ram size:

# yum install kernel-PAE

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