Hi, I have problems sending out e-mails from our Exchange Server. The public IP we have is a dynamic one, namely OUR_PUBLIC_IP.

Jan 21, 2017 - I'm getting an spf softfail from google. Spf=softfail (google.com: domain of transitioning me@domain.com does not designate 1.2.3.4 as. I'm getting an spf softfail from google. Spf=softfail (google.com: domain of transitioning me@domain.com does not designate 1.2.3.4 as permitted sender) Now, I fully understand that I can add 1.2.3.4 to the spf record and it should all work.

I have the DynDNS client which updates the current IP and maps it to ourdomain.dyndns.com. All good until now. For receiving the e-mails we use the mail server from our mail provider (part of the hosting packet).

Download DiskGenius(Now Renamed Partition Guru). Recover photos, videos and music files Support all popular professional RAW photo files Support most kinds of music, photo, file storage device To recover and save the files to your disk you will need to purchase the full version of the software. Free download DiskGenius to recover lost data & partition, manage disk capacity, backup Windows and personal data and fix disk issues on PC and The downloaded application is Free Edition which can be upgraded to Standard Edition or Professional Edition. You can test the free version before. Free full download.

There, we have a DNS zone implemented, which also has MX records and SPF TXT records. It's something like this: ourdomain.com MX mail.ourdomain.com 10 mail.ourdomain.com A PROVIDER_MAIL_SERVER_IP PROVIDER_MAIL_SERVER_IP PTR ourdomain.com We wanted to use our exchange server for sending e-mail form internal domain to the outside world (and not the mail.ourdomain.com server) so I added another MX record which points to ourdomain.dyndns.com.

In DynDNS records, ourdomain.dyndns.com points to OUR_PUBLIC_IP. Now the DNS records in our DNS zone looks like this: ourdomain.com MX mail.ourdomain.com 10 ourdomain.com MX ourdomain.dyndns.com 20 mail.ourdomain.com A PROVIDER_MAIL_SERVER_IP PROVIDER_MAIL_SERVER_IP PTR ourdomain.com The problem is that when I send an e-mail, it's delivered for some domains (i.e. Gmail) but for others (i.e.

All the sent e-mails are marked with SoftFail stating the following: domain of transitioning email@ourdomain.com does not designate OUR_PUBLIC_IP as permitted sender Also we cannot add a PTR record for OUR_PUBLIC_IP (is dynamic). If I make a reverse lookup, OUR_PUBLIC_IP is mapped to a subdomain of the internet provider which is something like this: abc999@myisp.com and is changing everytime the IP changes. From what I know, the destination MX server will make a reverse lookup for the IP sending the e-mail and if its associated domain isn't listed as an MX record it will flag the mail with SoftFail or worse: reject it. I think here is the problem: destination MX makes a reverse lookup for OUR_PUBLIC_IP and receives abc999@myisp.com insted of ourdomain.dyndns.com which is listed as an MX record. Obviously the abc999@myisp.com is not listed as an MX record (and couldn't be, because it's changing for each OUR_PUBLIC_IP we are assigned). My question: Is there any technical solution for this problem, except the static IP solution? You have 2 separate issues here, your SPF record and sending email from a Dynamic IP: SPF MX records are for email to your domain.

If you want to only send email from your Exchange server then you don't want to add it as an MX. You can add it to your SPF record, as an a: record: v=spf1 a:ourdomain.dyndns.org ip4:192.0.2.4 -all Remember, the SPF record is for listing the servers that send email for your domain. That however brings us to the second part of the problem.

Sending email As RotBlitz said, and as is, few mail servers will accept email directly from a Dynamic IP range (which will probably include any static IP you get from your ISP). You can relay through your other mail server (if there is no technical reason why you can't), your ISP or the. Edit Eventually we will get a SendLabs SMTP service for backup purposes after we switch to fully work with our Exchange server. SendLabs SMTP isn't a backup MX service, but only for sending email. I will try at first to add a SPF entry and see the result.

Don't you think that 'v=spf1 mx -all' is more appropriate ( is listed as an MX)? I don't have an A record for dyndns because it's dynamic, and don't now either the exact address pool for my dynamic IP. No - using mx in an SPF record is usually a sign that you don't know what you're doing with SPF. Amongst other things it forced more DNS lookups than is needed.

You can use your DynDNS hostname in the record, as I've said. If you need more help with the SPF record you need to let us know the DNS hostname of every device that sends email for your domain, and which has a static IP.

Edit I just have a question: the difference between v=spf1 mx -all and v=spf1 mx ~all is that the latter triggers a softfail flag and the former a denial if the sender isn't listed as MX? Yes, for recipients that use SPF. I'd also suggest you and the other SPF documentation. Thank you for the respnses. I know that MX server is for receiving e-mails, I think my misunderstanding was related with the verification the destination domain is doing. I thought (I just assumed, didn't checked) that verification is based on the MX entries you have, but it seems that it's wrong assumption and it's based on SPF entry like Cry Havok said.