Leaked emails from the Middle Eastern television channel al-Jazeera reveal that staff were divided on how to respond to the fatal attack on the staff of the French satirical magazine Charlie Hebdo.

Some journalists and editorial staff branded the publication as “racist” and “extremist” while others defended the right to publish cartoons depicting the prophet Muhammad.

The emails, published in full by the National Review, begin with one sent to staff by Salah-Aldeen Khadr, the London-based editor and executive producer, on Thursday suggesting a list of questions that should guide their coverage of events.

He said it should be “the best it can be” but asked staff to question whether the terrorist attack was “really an attack on free speech”, asking if an “attack by 2-3 guys” on “a controversial magazine” was equal to a “civilizational attack on European values”.

He suggested that the massacre could be viewed as a “clash of extremist fringes” – implying Islamic fundamentalists were on one side and staff at the magazine on the other.

Quoting from an article published in Time after Charlie Hebdo’s offices were firebombed in 2011, he said: “Defending freedom of expression in the face of oppression is one thing; insisting on the right to be obnoxious and offensive just because you can is infantile. Baiting extremists isn’t bravely defiant when your manner of doing so is more significant in offending millions of moderate people as well. And within a climate where violent response – however illegitimate – is a real risk, taking a goading stand on a principle virtually no one contests is worse than pointless: it’s pointlessly all about you.”

The email sparked a heated response. The US-based correspondent Tom Ackerman responded by quoting an excerpt of a New York Times article by Ross Douthat. It read: “If a large enough group of someone is willing to kill you for saying something, then it’s something that almost certainly needs to be said, because otherwise the violent have veto power over liberal civilization.”

Mohamed Vall, based in Qatar, who reported for the TV station’s Arabic-language service before joining its English wing, said supporting Charlie Hebdo risked encouraging more killings. “And I guess if you encourage people to go on insulting 1.5 billion people about their most sacred icons then you just want more killings because as I said in 1.5 billion there will remain some fools who don’t abide by the laws or know about free speech.

“What Charlie Hebdo did was not free speech it was an abuse of free speech in my opinion,” he said. “Go back to the cartoons and have a look at them! It’s not about what the drawing said, it was about how they said it.

“I condemn those heinous killings, but I’M NOT CHARLIE,” he wrote.

Jacky Rowland, the Paris correspondent, reminded others of the hashtag #journalismisnotacrime, which the channel had promoted in the wake of the arrest and jailing of three al-Jazeera journalists in Egypt.

• This article was amended on 19 January 2015 to clarify that in a passage of his email to al-Jazeera staff, Salah-Aldeen Khadr was quoting from an article published in Time after the Charlie Hebdo offices were firebombed in 2011.