What does 1 Corinthians 16:17 mean?

In the previous two verses, Paul commended the household of Stephanas for their devoted service to all the Christians in Corinth. He also told the Corinthian believers to submit themselves to servant leaders such as the Stephanas household, along with others who work hard to serve the church.

The reason for mentioning Stephanas in this part of the letter now becomes clear. Stephanas was one of three Corinthian men who came to visit Paul in Ephesus. These included Fortunatus and Achaicus. It's possible that the three of them brought a letter from Corinth to Paul containing some of the questions Paul has responded to in this letter (1 Corinthians 7:1). It's also possible that these three returned to Corinth with this letter from Paul; another possibility is that Timothy was the one who brought it to them (1 Corinthians 16:10).

Paul writes that the arrival of these three men makes up for the absence of the rest of the Corinthians. By this he seems to mean that he has truly been missing the Corinthians after moving away, and spending time with these visitors from there has helped with that sadness at being separated from them.