Biju Abraham N. wrote:
> Dear All,
>
>
>
> We have an exim4 4.69-9 running on a debian linux box. We have two internet
> service providers and as a protection, assigned one public IP each from two
> pools on the mail server machine. I have got mapped the second ISP's public
> IP also in the DNS with MX priority 20 as follows while the first one has
> priority 10:
>
> rajagiritech.ac.in. 3600 IN MX 10 mail.rajagiritech.ac.in.
>
> rajagiritech.ac.in. 3600 IN MX 20
> mailback.rajagiritech.ac.in.
>
> mail.rajagiritech.ac.in. 3600 IN A 202.88.229.124
>
> mailback.rajagiritech.ac.in. 3600 IN A 115.248.202.19
>
>
>
> I also listening on port 25 for both the public IPs for incoming mails and
> if the primary ISP fails, mails will come in through the second ISP.
>
> Now while sending mails, I have seen that there are rejections on the second
> ISP's public IP as follows:
>
>
>
> SMTP error from remote mail server after end of data:
>
> host gmail-smtp-in.l.google.com [74.125.155.27]:
>
> 550-5.7.1 [115.248.202.19] The IP you're using to send mail is not
> authorized to
>
> 550-5.7.1 send email directly to our servers. Please use the SMTP relay
> at your
>
> 550-5.7.1 service provider instead. Learn more at
>
> 550 5.7.1 http://mail.google.com/support/bin/answer.py?answer=10336
>
> u4si2912443ybi.99
>
>
>
> How do I avoid such errors? Should I fully prevent sending mails from the
> second public IP OR can I do something by which I still can send mails from
> second public IP and other mail servers will receive them with no error? Can
> somebody please help me?
>
>
>
> Regards,
>
> Biju.
>
*Receiving* should be OK with the MX (or even the 'A') RR.
Sending is another matter:
# host 202.88.229.124
124.229.88.202.in-addr.arpa domain name pointer 124.229.88.202.asianet.co.in.
# host 115.248.202.19
Host 19.202.248.115.in-addr.arpa. not found: 3(NXDOMAIN)
What you *want* is PTR RR on both of those (or whatever else you use for
'outbound') that agrees with your <domain>.<tld>, MX records (and HELO string to
be pedantic). IOW .. rajagiritech.ac.in AND NOT '...asianet.co.in'
Your provider, if the principle IP block 'holder' can place those RR in their
DNS for you. That's where they are expected to be.
Feel free to email me directly to test before and after.
I may not be as 'polite' as GMail, but reject for the same reasons..
HTH,
Bill
