It was Jake Delhomme, the quarterback who played under Fox during seven seasons together in Carolina, congratulating him on Sunday's win against the Chiefs.
"You're doing it the Foxy way -- I love it!" Delhomme wrote, as recited back by the coach.
"So what exactly is the Foxy way?" I asked.
Fox paused. He smiled. And with the most laid-back, charismatic attitude of any coach in the NFL, he explained it the only way anyone could rationalize a 17-10 win that included just eight passes by quarterback Tim Tebow, against 55 running plays.
"Do whatever the hell it takes," he laughed. "I mean, what the hell? You don't get points for style in this league. Let me tell you something: My man is really good in this offense. You know what I mean?
"If we were trying to run a regular offense, he'd be screwed."
Fox then swung his chair toward the wall to his left, opposite the windows overlooking the mountains. He threw his feet up on his desk, fired up a large mounted television and grabbed a remote designed to shuffle through game tape.
'We can't do that other crap'
"After the loss to Detroit (a 45-10 blowout), we decided if Tim is going to be our guy, we can't do that other crap," Fox said. "We had to tweak it."
It was after that loss when Fox and the rest of the organization began a two-week transformation that included a change in play-calling. The resulting success in turn led to a change in the attitude toward Tebow Time.
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Against the Raiders, Fox said the staff implemented eight new plays, mostly out of the read-option offense that Tebow so successfully mastered at the University of Florida. Then, against the Chiefs, they took it even further, adding the dive (triple) option, which rarely has been used in this generation's NFL.
"What he does against conventional teams is rush the passer. Well, we don't have a passer. We have a runner. Not to say he can't pass at all, but we're recognizing his strengths."
The play results in a respectable gain, but Fox is making a greater point: The looks Denver has received from opposing defenses in the past two games has opened the door to more creative ways to exploit teams with Tebow's skill set.
"I don't think anybody has ever done it quite to the extent we're doing it," Fox said, again referencing the current-day NFL option.
This is still a challenge for Fox, don't get that wrong.
'Timmy is fine'
Even as Fox has decided to fully embrace Tebow's potential by tailoring the offense to him -- and even though he constantly praised Tebow's unorthodox skills Tuesday like a kid showing off a new toy that nobody else has -- this is still a strange deal.
Proof enough occurred in the middle of the film session, when I asked Fox if he himself would have drafted Tebow, who was picked in the first round in 2010 by Josh McDaniels, the coach whom Fox replaced.
"That's hard to say," Fox said. "As a football player, I would have. He's what you're looking for in a football player."
Without a pause, Fox's attention immediately went back toward the television screen as he began to explain another play, a symbolic moment since it explains exactly the current mentality: Don't overthink this thing. Don't overanalyze it.
"Here's our dive option," Fox says. "We'll get better at it. This is the first week we've done it."
He jumps forward to another one of the team's new read-option plays.
"See the tight end? He's got to be flatter in arc," Fox says. "That'll suck the support guy up. See how he's steep? He needs to be more down the line so Timmy can be more downhill at the end. We've got to get better at that.
"See the right tackle? He needs to come up and block the backside backer, who gets in on the play. Timmy is fine. He's done this his whole life. It's the rest of the guys that are learning it. We just put this in two weeks ago."
'Wait and see'
It remains among the NFL's greatest wonders if the Broncos can sustain success in a system led by Tebow and so diluted with runs. Part of finding out will be dictated by the progress of the players around Tebow, which is another element of an evaluation process like few others in league history.
Heck, he's the one who implemented the Wildcat (before it was called the Wildcat) with Chris Weinke at quarterback in Dec. 2006 when the Panthers played the Falcons. In that game, Carolina passed seven times and rushed 52 times in a 10-3 win.
Only 32 times since the 1970 AFL-NFL merger has a team attempted fewer than 10 passes and logged more than 50 rushes. Fox now accounts for two of those instances.
"Hey, as long as you're moving the ball, possessing the ball, giving your defense some rest, it's all good," Fox said. "Run, pass, if they let you kick it down the field, I wouldn't mind doing that either. As long as you're moving the ball, that's the key."
This is Fox's plan, and he's going to keep pushing it.
Will it continue to work? Will Tebow manage to keep winning games, and as a result, winning the opportunity to keep having this offense designed around his skill set? Everyone is watching. Everyone is wondering.
And as far as Fox is concerned, no matter what it takes to do so, everyone is going to eventually find out. That, in a nutshell, is the Foxy way.
"At the end of the day, if you coached in college football, you saw the option every week," Fox said Monday. "It's just been taboo in the NFL. Everyone is looking for that prototypical quarterback. And the truth is, there aren't very many of them.
"Hey, Tim thinks he deserves to have these plays in this offense. And you know what? After watching our games the last two weeks, it's hard to argue with him."