Emails get bounced when sending to a gmail account

[tomwanted]

Hi, i have my email, domain and hosting with talktalk business- have done for a long time sice they took it over from F2S. With Googles recent change in security checks, im now having all my mail to anyone with a gmail account bounced with the below type of failure notice. I have no idea how to sort this problem or even if its something i can sort? As far as Googles notes say- this shouldnt be happening if youre sending to people youve already had contact with but its literally any gmail account. Anyone know how i get this issue fixed?

 142.250.102.27 failed after I sent the message.
Remote host said: 550-5.7.26 This mail is unauthenticated, which poses a security risk to the
550-5.7.26 sender and Gmail users, and has been blocked. The sender must
550-5.7.26 authenticate with at least one of SPF or DKIM. For this message,
550-5.7.26 DKIM checks did not pass and SPF check for [mostlywanted.com] did
550-5.7.26 not pass with ip: [85.119.248.222]. The sender should visit
550-5.7.26 https://support.google.com/mail/answer/81126#authentication for
550 5.7.26 instructions on setting up authentication. gb31-20020a170907961f00b00973943e596csi2672048ejc.698 - gsmtp
STARTTLS proto=TLSv1.2; cipher=ECDHE-ECDSA-AES128-GCM-SHA256; subject=/CN=mx.google.com; issuer=/C=US/O=Google Trust Services LLC/CN=GTS CA 1C3;

[tomwanted]

Thanks, i would literally have no idea how i would go about this so i will definitly drop the TTB domain admins a mail and see if they can sort it out for me. Thank you very much for your help, really appreciated!

[Gondola]

If you don't know how to add an SPF text file to your mail hosting DNS record then ask the TTB domain admins to do it for you. 

Your email is hosted by and sent by the APM-Internet mail servers so that's why you either need an SPF text record added to your DNS name servers or to reference the apm-internet.net SPF file. The text file you need is:

v=spf1 ip4:85.119.248.0/22

The domain admins will understand exactly what's needed to authenticate your domain mail sending.

Or if you have an active f2s.com email address to use as the return-path address on your outgoing mails then as that uses the same SPF file you will get the required authentication from that.

For a better understanding of SPF text files, their creation and publishing you may find this SPF guide courtesy of Mimecast of some help.

[tomwanted]

Thanks for that, made zero sense to me to be honest. I purchased domain, hosting and email way back in 2004 and have barely needed to do anything with it since. With my hosting i just have ftp access, no idea how to do anything re the DNS record and yeah- the host domain of mostlywnted.com is the return path. Is sending a mail to the talktalk domain admin the best way to get this sorted?

[Gondola]

Contact domainadmin@talktalkbusiness.co.uk

For full authentication of a personal domain you should check that the admins, or you if you have access to Control Panel for your hosting, have added an SPF file to your DNS record. There is no SPF file present for your host domain mostlywanted.com. I assume your host domain is set as the return-path address on your outgoing mail messages and this is the reason for the authentication fail.

If using the apm-Internet.net SPF file for authentication then the return-path address on your outgoing emails should reference an appropriate return-path address so the authentication checks will pick up and authenticate using the apm-internet.net spf file.

The f2s.com email addresses use the same SPF file so if you set the return-path for your personal f2s.com email address that would work.