Do apologize is a bureaucratic-sounding phrase best avoided in any genuine apology. The insertion of the helper word do ahead of apologize distances the speaker from the apology and hence the offending action, and this may only further infuriate the apology’s recipient. The effect is subtle, but consider how much more convincing these apologies would sound if do were removed:
“I do apologize very sincerely for the mistakes I have made,” he said. [Louisville Courier-Journal (link now dead)]
“We realize it’s been an ongoing issue and we do apologize,” TTC spokesperson Danny Nicholson told CityNews. [CityNews]
When asked to explain the blunder, a Liberal Party spokeswoman said it was “a simple error and we do apologise.” [Blue Mountains Gazette (link now dead)]
“So I guess I do apologize for causing any misleading information, but it was nothing, ever, of ill-wise about us or the Moose.” [quoted in Winnipeg Free Press (link now dead)]
Office manager Sylvia Hernandez said, “We do apologize for the inconvenience, but they do have water, they have heat, they have electricity; unfortunately, not all have hot water.” [Albuquerque Express]
As that final example demonstrates, nothing can rescue an apology that contains the numbing phrase for the inconvenience. Of course, following an apology with a clause beginning but also doesn’t help. Office manager Sylvia Hernandez might as well not apologize at all.