If you set the SPF record for your domain and you send your emails through the server smtp.forpsi.com, please, add into your SPF record this item:
Here is a sample of the value of SPF record with included item:
v=spf1 a mx include:_spf.forpsi.com ~all
Illustrated instruction of setting the SPF record
1) click on the "Domains" link
2) click on the domain name
3) click on the "edit DNS records" link
4) add the SPF record as a TXT record for the domain, the value can be v=spf1 a mx include:_spf.forpsi.com ~all
Note: It is neccessary to include into the SPF record the list of the IPs of the ISP mailservers, the internal servers etc., which you use to send your emails too. The SPF record above allows to send your emails only through Forpsi mailservers and from your web.
Note: The mechanism and qualifiers allow you to determine, how the emails, that do not correspond with allowed IP address, will be processed. Qualifier - (minus) for FAIL: the mail should be rejected. Qualifier ~ (tilde) for SOFTFAIL: a debugging aid between NEUTRAL and FAIL. Typically, messages that return a SOFTFAIL are accepted but tagged.
In the sample above "v=spf1 a mx include:_spf.forpsi.com ~all", the qualifier Softfail is used. Emails sent via our mailservers match the SPF test. Emails sent via other mailservers (e.g. SMTP server of the ISP) don't match the SPF test, but will be accepted.
If you choose the qulifier Fail (-all), not matched emails will be rejected. Choose this qualifier, if you exactly know, which servers you use for sending your emails and if you want to prevent abusing your domain in spams.