The phrase "after expressly" is correct and usable in written English.
It can be used to indicate that something occurs following a clear or explicit statement or action.
Example: "The contract will be enforced after expressly stating the terms agreed upon by both parties."
Alternatives: "following a clear statement" or "subsequent to an explicit declaration".
In 1996, the Food and Drug Administration, after having expressly disavowed any such authority since its inception, asserted jurisdiction to regulate tobacco products.
A memorial service planned for the Nilufar mosque in the capital's Abbasabad neighbourhood was called off after officials expressly forbade it.
When the same issue arose with Obama's war in Libya in the absence of Congressional approval (indeed, after Congress expressly rejected its authorization), State Department adviser Harold Koh was forced to repudiate Obama's own words and say he was wrong back then.
After having expressly laboured to avoid it for so long, the aim is not to create density directly, but to open the door and allow density to happen in our cities, thanks to more abstract and general planning rules.
After a boardroom tussle with JD over who decided to put walnuts in Team Elegance's brownie mixture ("You were Team Leader. The buck stops with you". "But you actually put a whole bag of walnuts in after I expressly told you not to" "The buck stops with you, mate"), Mukai is dismissed.
I can even, if I squint and furrow my brow a lot, vaguely envision the kind of bug that might cause an airline to send luggage to Korea three days after its owner traveled from San Francisco to his final destination of Toronto, and two days after he, forewarned, expressly told them not to do so.
Dispatched to Phnom Penh, Haig exceeded Nixon's instructions and told Lon Nol that the U.S. would continue to fight in Cambodia even after Congress had expressly forbidden further American incursions there and Nixon had agreed to that restriction.
After two years of expressly opposing such a policy, the Obama administration has officially announced that it will begin to directly arm the Syrian rebels.
Shortly after assuming office, he expressly called to account some of the most powerful industrial and financial leaders in the nation for what he deemed their malpractices in business affairs.
