Can I provide gas certificate by e-mail?

I am about to serve section 21 notice, where one of the requirements is to provide tenants with gas certificate.

  1. My conversations with tenants were always by e-mail - I sent gas certificate also by e-mail (but don’t have their confirmation)
  2. Openrent contract states “copy of the safety check record is given to the Tenant at the start of the tenancy” (could, but does not have to imply in person delivery)
  3. Openrent website suggests “If sharing an electronic copy with your tenants, be sure they first have the means to access it”

Can I still serve section 21 notice?
Is e-mail good enough to provide tenants with gas certificate?

I always get a form signed when I personally give the certificate You cannot beat this

I wish I did that, but it is too late, I guess.
Tenancy started in 2018