SPF

[WSH]

This thread goes back to April, but as licquorice has already said, SPF (Sender Policy Framework) is a type of DNS record. You cannot alter it, it has to be entered in the DNS record by your service provider.

[KevSully]

Yes I understand that.  Hence my comment about it.  The spf record was entered by 123 into the dns and I can see it on my domain management page.   
Yet sending to gmail still fails.  
anyone know what else it could causing the spf rejection.  Did 123 enter the wrong SPF record? 
I can send to all other email addresses except any gmail email.  

[WSH]

I take it the mail exchange server address (the mx) is correct for your mail server?

[bluejak666]

I followed the instructions here and entered an SPF. However a small proportion of my emails to gmail eddresses still fail. I think the fault is with gmail, ie insoluble. 

[KevSully]

I’ve no idea what the mx is     
the record 123-reg put in my DNS  is 

v=spf1 include:secureserver.net -all

I am assuming they know what they are doing. 
they tell me this fixes Gmail bounce backs.  
but ??? 

[licquorice]

See message 4, add those details to your record