The postboxes on West Street were overflowing last Thursday evening (December 15), with letters found scattered around.
Caitlin Charlier then found dozens of opened and unopened cards outside the Swan pub at about 5.30pm on Saturday.
Caitlin collected and reposted the unopened cards into another postbox.
The latest strike organised by the Communication Workers’ Union (CWU) took place last Wednesday (December 14) and Thursday (December 15), with further strike action planned today (Friday) and tomorrow (Christmas Eve).
A Royal Mail spokesperson said: “We would like to apologise to any customers impacted by damaging CWU industrial strike action. We are looking into clearing the postboxes as quickly as possible.
“We are doing everything we can to deliver Christmas for our customers, and would like to thank the increasing number of posties returning to work each strike day, temporary workers and managers from across the business who are helping to keep the mail moving.
“The security of our customers’ mail is a high priority for Royal Mail, and we are looking into what happened in Haslemere on these occasions.”