SPF and DKIM Check

You can now send a test email from your mail server to your Gmail account to see if the SPF and DKIM checks are successful. On the right side of an email opened in Gmail, click the show original button from the drop-down menu to see the verification status:

SPF:     PASS with IP XXX.XXX.XXX.XXX Learn more
DKIM:    'PASS' with domain example1.com  Learn more
DMARC:   'PASS' Learn more

Our Postfix server also performs SPF and DKIM checks when receiving mail. You can see the results in the headers of the mails you received. E.g:

Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2607:f8b0:4864:20::c2d; helo=sender-domain.com; envelope-from=xxx@sender-domain.com; receiver=<UNKNOWN> 
Authentication-Results: example1.com;
	dkim=pass (2048-bit key; unprotected) header.d=sender-domain.com header.i=@sender-domain.com header.b="XWMRd2co";
	dkim-atps=neutral

You can also go to https://www.mail-tester.com. You will see a unique email address. Send an email from your domain to this address to get your score.