A few years back, I still telling many to use SPF to prevent outgoing email domain spoofing. For today, it is more than SPK record, DKIM & DMARC have become a must to prevent email domain spoofing and enhance your email delivery.
However, many still do not have these in their DNS records or just SPF. I personally think this is the moment to have all these 3 if you have not published them for your domain.
There are just too many spam, scam and phishing emails out there. Many email server administrators have tightened their email security, while this filtering rule is tighter, missing records on your domain DNS can be caused delivery failure if they are verifying, also receiving more spam emails.
Thus, it is important to implement all these three items. Modern control panels like cPanel or Plesk is just a few clicks away to seitch on SPF and DKIM. For DMARC, just Google and it is not difficult to have one too.