Mercury Retrograde (approximately a 4 week period that occurs 3 times a year) is a good time to go back over situations, relationships etc... and do the "re" words, such as redecorate, re-examine, research, reorganize, re-evaluate, it is not a good time to launch new endeavors or sign new contracts, buy new big ticket items such as cars, houses, etc...
But if you are "re-looking" and re-evaluating a situation, anything career related or working on a current or recent relationship, you can proceed during this time, because it's a continuation from something previously started, (can be in any area of your life) still move forward and double check all forms of communication, but still remain open minded and flexible.
From Astrologer Susan Miller on Mercury Retrograde:
"Indeed, despite what I have just said, there are situations where you can move forward, gingerly, during Mercury retrograde. The main time you can is if you are going back to the past, either to correct something or do more with a person you know and admire.
If your editor gives you an assignment that was put on the back burner a year ago, and it has jumped to life again, proceed!
Here is another example: Let’s say you are out of work and looking for a new job. Your old boss (whom you enjoyed working with on a previous job) invites you to join the company he is at now, as a member of the team. In this case, you will be going back to a former professional relationship that you actually started a long time ago, and this is simply an ongoing situation. In this case, you CAN take the job.
Readers ask, “Well, I started interviewing for a new job before the retrograde, but the offer for the new job was made after Mercury retrograde. Technically, I knew the interviewer for a few weeks before the retrograde, so can’t I take the job?” Actually no. In this case, you have had no real history with this interviewer or company. Sorry, this does not apply. However, if you are desperate and badly need to find a job, take it, but realize it will not be a long-term solution. You may be out looking again soon, possibly because you don’t like anything about that new job. That may be fine with you, for at least you will have income for a short time, which is better than no income at all. Also, it is said to be easier to find a new job after you have one, so in that sense, it may be helpful to take a short-term, stopgap job.
What if you gave a bid on a house you loved and wanted but that was rejected. Can you go back and put in a new bid on that same house during the retrograde, even months later (assuming the house is not yet sold)? Yes. In this case, you have a history with the house, the people who live there, and your broker. This would actually be a good time to “redo” your bid and send it in again. When it comes to exceptions, if you have a history with the person or situation, you can proceed carefully during the Mercury retrograde period."