OTTAWA -- Porter Airlines has been fined $150,000 for violating the CRTC's anti-spam legislation.

The CRTC says the Toronto-based airline has agreed to pay the fine for sending emails without an unsubscribe button or one that was clearly labelled.

The federal regulator says Porter was also unable to provide proof of consent from each email address that received its commercial emails.

The CRTC says the violations took place between July 2014 and April 2015.

Porter spokesman Brad Cicero says the problem arose as the airline was transitioning to a new email platform and there were some "isolated errors."

Cicero says the problem wasn't immediately obvious to the company but it rectified it as soon as it became aware.

The regulator says as part of the agreement with the company, Porter has agreed to improve its compliance training for the anti-spam legislation.

Since last July, the regulator has also fined online dating website PlentyOfFish and corporate training company Compu-Finder for unwanted email messages.

"Some businesses are under the mistaken impression that they are compliant with the law by relying on general business practices or policies as proof of consent," said chief compliance and enforcement officer Manon Bombardier. "This is simply not the case."