[clin_]

Your confirmation email was sent to my spam folder.

Here's some things you can do to make your email look less like spam:

1.) Use Sublimall in the from field (never leave the from field blank).

2.) Include a physical address for your company somewhere in the message body.

3.) Use better english and include an explanation of what this email is, what triggered it, instructions to ignore the email if the recipient didn't request it.

[agildehaus]

It's more likely improper DNS settings. Possibly sending from a server not listed in the MX record and not explicitly allowed by an SPF TXT.

[TobbenTM]

Correct.

MX Settings OK, SPF not OK.

[eli]

A physical address and unsubscribe instructions are actually required by US CAN-SPAM law.

[xentronium]

Also if you only send html email, adding plaintext version might help.

[druska]

Same thing happened to me