How to update DNS with SPF to validate outbound email

Why is my email being sent from admin@booking-manager.com?

If you are getting e-mail notices from Booking Manager from admin@booking-manager.com instead from the actual e-mail address you are using, that means that you have Sender Policy Framework (SPF) record defined in your domain settings (DNS).

SPF is a useful security feature that identifies which email servers are allowed to send email on your behalf, and prevents unauthorized servers, such as spammers to send emails in your name.

If your DNS settings have this feature and Booking Manager server is not allowed to send emails in your name, it will be sent from admin@booking-manager.com to ensure uninterrupted the delivery of notifications.

The Solution

In order to allow e-mails to be send on your behalf you need to allow Booking manager mail server to do that in your SPF record. This is an example for Gmail users:
v=spf1 a mx ip4:148.251.70.208 ip4:136.243.83.28 ip4:148.251.236.140 ip4:46.165.204.101 include:_spf.google.com include:booking-manager.com include:mmksystems.com ~all

For more detailed information you can read https://technet.microsoft.com/en-us/library/dn789058(v=exchg.150).aspx

Multiple SPF records are not allowed

Common mistake when setting up additional SPF servers in your DNS settings is to add a new record instead of changing the existing one. Only one SPF record is allowed. You can read more detailed explanation here: https://support.google.com/a/answer/4568483?hl=en