Craig Houston, founder of Sons of Struth, was defiant after two sheriff officers delivered the letter yesterday, demanding he stop using one of the bus company executive's e-mail addresses in the online petition, which calls 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 address.
But Mr Houston said last night he would not be complying.
Change.org, the site on which the petition has been set up, 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 within 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."
He added: "All this is, is one lawyer giving me their indication of how the law lies. All I seeis 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 you are asked who you want the petition to be sent to."
In March, the Ibrox director threatened to sue Mr Houston over what he described as "libellous comments" but reached agreement with the Sons of Struth founder.
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."
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