An Post processed 3.5 million Christmas cards and letters last night alone.
Its Head of Communications Anna McHugh said that the volume of business has gone "absolutely through the roof" this Christmas.
The 3.5 million cards and letters that went through its system last night were all posted between Sunday morning and yesterday evening.
Ms McHugh said that this is a "huge volume" of Christmas mail for a window of less than 48 hours.
"Traditional mail volumes have been falling steadily for the past 20 years, but Christmas holds up in Ireland," she added.
"The Christmas card is a great tradition that is still well and truly alive in Ireland."
She said that regarding packages, An Post is "doing double what we did in the Christmas before the pandemic".
Ms McHugh attributed this to a surge in online shopping and said that it is clear that Irish companies have made the transition to "major online players".
She outlined the key deadlines for ensuring delivery for Christmas.
"For the Republic of Ireland, letters and parcels, the absolute last date is 22 December, which is this Thursday."
We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences
Today is the last day to post to Northern Ireland.
The latest guaranteed date for letters going to Europe and England, Scotland and Wales was yesterday.
Post offices will be open all week, with a half day on Saturday.
