Pursuant to Florida Statute 83.56, the delivery of the 3 day written notice must be by mailing or delivery, if the tenant is absent from the premises, by leaving a copy at the residence.
Dear "Can the 3 day notice be sent as email or text?":
No, it must be printed on paper and (1) delivered by hand, (2) delivered by taping on front door, or (3) mailed. There are certain elements which must be satisfied and the listing of the unpaid rent owed is one of the elements.
After the comply-by date is over, then the landlord can file on the next business day at the courthouse.
If you are a landlord, I highly recommend joining a local landlord organization (not an investors' group) and buying a recently-published book for Florida Landlords. Replace the book every year or every two years.
If you are the Tenant and you feel that the Pay or Quit Notice aka three day notice contains some errors, see a local landlord tenant lawyer or real estate attorney for a consultation. There may be something they can do about it for you. Good luck. There is a tab above to Find A Lawyer and you can also call the state or county bar association.
Both of my colleagues correctly state that a 3 day notice may be sent via mail. I comment only to add that I have often seen procedural problems when the 3 day notice is mailed. Often the landlord does not take into account the need to add at least an additional five days to account for the mailing. If at all possible it is always my recommendation that the landlord attempt to hand deliver the 3 day notice and post at the same time. It is also my recommendation that the landlord use either the smartphone or digital camera to take a picture of the posting. As the saying goes a picture is worth a thousand words, and a digital photograph with the time/date stamp on it goes far when there is a contention that the landlord did not properly deliver the notice.