The Ottawa-Carleton District School Board has sanctioned Barrhaven/Knoxdale–Merivale trustee Donna Blackburn over an email last October in which she accused one of her colleagues of being arrogant.

An investigator brought in to handle a formal complaint from Somerset-Kichessippi trustee Erica Braunovan said the email was sent Oct. 29, hours after Braunovan found out she had lost the provincial NDP nomination for Ottawa Centre.

"I trust now moving forward you will now put the interests of the OCDSB above that of your personal political goals," Blackburn wrote under the subject line "OCDSB first?"

"I have no doubt, given your arrogance you will run yet again for another nomination."

That email was copied to board chair Shirley Seward.

The next morning Braunovan wrote back, copying several other trustees, asking Blackburn to stop the "mean-spirited" messages, and claiming she felt harassed.

Blackburn replied, denying she had sent any other emails, and saying she was worried about the board's reputation.

Blackburn did not talk to investigator Andrew Tremayne, nor give a written statement.

Trustee Erica Braunovan told the investigator she found the email insulting, disrespectful and mean-spirited. (CBC)

Braunovan told the investigator she decided to stand up for herself and file a formal complaint after a reporter contacted her, saying they had a copy of the email exchange.

According to Tremayne, Braunovan told him she found the emails insulting and disrespectful.

His report was finished Jan. 23, and the board voted to censure Blackburn at a meeting Tuesday night, ruling she had breached sections of its code of conduct.

The board could have voted to exclude Blackburn from a board meeting, or from one of its committees for six months.

Reached by CBC News Wednesday afternoon, Blackburn declined to comment.