Array
(
    [aspmx.l.google.com] => 1
    [alt1.aspmx.l.google.com] => 5
    [alt2.aspmx.l.google.com] => 5
    [aspmx3.googlemail.com] => 10
    [aspmx4.googlemail.com] => 10
    [aspmx5.googlemail.com] => 10
    [aspmx2.googlemail.com] => 10
    [colef.mx] => 0
)

try aspmx.l.google.com:25

<<<
220 mx.google.com ESMTP a19-20020a1709027d9300b001dcaf709f55si12838017plm.207 - gsmtp

>>>
HELO colef.mx

<<<
250 mx.google.com at your service

>>>
MAIL FROM: <edelman@colef.mx>

<<<
250 2.1.0 OK a19-20020a1709027d9300b001dcaf709f55si12838017plm.207 - gsmtp

>>>
RCPT TO: <jontiveros@colef.mx>

<<<
250 2.1.5 OK a19-20020a1709027d9300b001dcaf709f55si12838017plm.207 - gsmtp

>>>
RSET

<<<
250 2.1.5 Flushed a19-20020a1709027d9300b001dcaf709f55si12838017plm.207 - gsmtp

>>>
quit

<<<
221 2.0.0 closing connection a19-20020a1709027d9300b001dcaf709f55si12838017plm.207 - gsmtp

Array
(
    [hotmail-com.olc.protection.outlook.com] => 2
    [hotmail.com] => 0
)

try hotmail-com.olc.protection.outlook.com:25

<<<
220 CH3PEPF00000010.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Thu, 25 Apr 2024 15:04:40 +0000

>>>
HELO colef.mx

<<<
250 CH3PEPF00000010.mail.protection.outlook.com Hello [52.43.241.46]

>>>
MAIL FROM: <edelman@colef.mx>

<<<
550 5.7.1 Unfortunately, messages from [52.43.241.46] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3140). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [CH3PEPF00000010.namprd04.prod.outlook.com 2024-04-25T15:04:40.928Z 08DC641F8F1BEC1C]

>>>
RCPT TO: <macrij_12@hotmail.com>

<<<

>>>
RSET

<<<

>>>
quit

<<<