The current mercury retrograde is from May 29th to June 22nd, with a 2-3 week shadow period on either side. People don't always give it enough importance because it takes 9 weeks without the shadow and up to 18 weeks with the shadow periods. Not all mercury retrogrades have the same power. It depends on the astrological climate that is happening during the time. Retrogrades that occur at the same time of eclipses always have a lot more power, and capacity to cause bigger issues.
Traditionally mercury when retrograding will cause misunderstandings in communications, ensure trouble later when you sign a contract or begin a new venture, or cause delays in things working out as expected. It is not a good time for buying electronics, or other purchases related to communications. Things get lost or delayed in the mail more often, and people have different expectations when signing contracts. For example, terms were unclear, not addressed in writing or not discussed at all, and assumptions made without asking specific questions.
Retrogrades are best for revising and revisiting things from the past rather than starting anything new. Oral and written communication when published during a retrograde often has to be edited again, and sent out in revised form. It is not auspicious to start a new job or launch a business on Mercury retrograde.
What has been your experience with mercury retrograde?