Overstayed in 2013 (125 days) - Going back to Spain this August

[AmericanTraveler]

Me: American

I went to Europe on April 3, 2013 (first port of entry was Munchen, but I was in Italy for 3 months) I ended up taking an extra 40 days to walk the Camino in Spain and did not leave the Zone until August 6, 2013 via Calais to UK.  Note, my passport does not have an exit stamp from the French side only on UK before taking the auto-train.  The French side never mentioned the overstay upon leaving or mentioned a fine \ ban.

This meant I was in the zone for a total of 125 days.  I have not been back since.

I'd like to go back to Spain for a month specifically flying to Madrid then on to Santiago de Compestella and rent an AirBnB house for a month.  I work for a US Tech company and can work from home when I want.

It has been 4 years now, will anything happen at the airport in Madrid if I go back in August.  As an American I do not need to apply for Schnegen entry in advance but should I contact someone beforehand?

It is only a matter of time before I am asked to go to EU for a conference or to visit an office so I'd like to go now to make sure there wont be future issues.

[bugibar]

You are fine. An overstay can be punished at latest upon departure from the Schengen zone. If it is not detected at the border control when you leave, then it is neglected. As of now, having been out for 4 years, you satisfy the 90/180 rule too.