Craig Houston, founder of Sons of Struth, remained defiant after two sheriff officers personally delivered the letter yesterday, demanding he stop using one of the bus company executive's e-mail addresses in the online petition which allows supporters to call for the Rangers board to issue a legally binding assurance that Ibrox will not be sold or used as security for loans.
The letter from solicitors Levy and MacRae warns that if Mr Houston does not act, they will seek a court order to prohibit his use of the business e-mail address. But Mr Houston said last night he would not be complying.
Change.org requires that people input the e-mail addresses of the decision-makers, who are notified every time someone signs the petition.
With the Rangers petition, which was signed by more than 5500 people in the first 48 hours, both Mr Easdale and Rangers chief executive Graham Wallace are automatically sent e-mails.
Mr Easdale is objecting to the use of his McGill's Buses e-mail address and claims he is being harassed and caused needless anxiety. Mr Wallace receives the e-mails through his official Rangers account.
Asked if he would comply with the demand, Mr Houston said: "No."
Asked if that meant he was willing to take his chances in court, he said: "All this is is one lawyer giving me their indication of how the law lies. All I see, is this is another idle threat.
"Mr Easdale won't be alone in getting e-mails as there are loads of businesses which have got petitions on that site about them. When you subscribe to the petition you are asked who you want the petition to be sent to.
"I don't know the law, but if it was illegal, then I wouldn't imagine someone who specialises in running a petition would provide a facility to do it [input email addresses]."
It is the second time Mr Easdale, chairman of Rangers' football board, has threatened action against the Sons of Struth founder. In March the Ibrox director threatened to sue Mr Houston over what he said were "libellous comments" but the two reached agreement.
Mr Houston said: "It is not his private e-mail address but another business address I got. I had asked on more than one occasion to be provided with e-mail addresses of all the Rangers directors and that was ignored.
"So I used what I had."
A spokesman for Mr Easdale said: "It would have been understandable had the e-mails been going to Mr Easdale's Rangers address, but they are going to his private business address and he and his legal advisers regard that as an unwarranted intrusion."