Hola y Saludos
Te aconsejo que crees un SPF record para que tu servidor sea aceptado en otros ISP providers, de esta manera te veran como servidor de correo legitimo.
http://www.openspf.org/SPF_Record_Syntax
Evaluation of an SPF record can return any of these results:
Result |
Explanation |
Intended action |
Pass |
The SPF record designates the host to be allowed to send |
accept |
Fail |
The SPF record has designated the host as NOT being allowed to send |
reject |
SoftFail |
The SPF record has designated the host as NOT being allowed to send but is in transition |
accept but mark |
Neutral |
The SPF record specifies explicitly that nothing can be said about validity |
accept |
None |
The domain does not have an SPF record or the SPF record does not evaluate to a result |
accept |
PermError |
A permanent error has occured (eg. badly formatted SPF record) |
unspecified |
TempError |
A transient error has occured |
accept or reject |
Examples:
"v=spf1 mx -all"
Allow domain's MXes to send mail for the domain, prohibit all others.
"v=spf1 -all"
The domain sends no mail at all.
"v=spf1 +all"
The domain owner thinks that SPF is useless and/or doesn't care.
Suerte