An Post has reported an operating profit of €8.4m for last year, a significant turnaround from its €12.4m loss in 2016.
The return to profit came on the back of a 1.2% rise in revenues to €840m while costs also fell at the company.
Last year the price of a standard stamp rose from 72 cent to €1.
An Post said this increase and the "massively" increased parcel volumes offset traditional mail volume decline from e-substitution brought revenue back to 2008 levels.
The company said that when gains from the sale of its Cardiff Lane site and a refinancing dividend from Premier Lotteries Ireland of €9m are included, it posted a pre-tax profit of €49.6m for the year to the end of December.
An Post's CEO David McRedmond said the company achieved a substantial turnaround of its business to move back into growth and profit.
"With the restructuring into two core businesses, the reinvigoration of management, the collaboration with the staff and unions, and the backing of Government, the future is bright," David McRedmond said.
"An Post is the enabler of e-commerce, and will play an increasingly important role partnering the digital economy," he added.
During 2017, An Post undertook a major strategy review which saw the company split into its two major businesses, the Mails and Parcels Service and the Post Office Network.
As part of the restructuring, the management team has been reduced from 11 to six executives while An Post's overall workforce was also reduced by 333.
The company also redesigned its parcels service and said the extension of the delivery service to Saturdays and late-night cut-offs has allowed it to regain significant share of the burgeoning parcels market and achieve 30% year-on year volume growth.
"An Post is rapidly growing share with key UK and international e-commerce brands as a trusted partner for both the shipper and the shopper," the company added.
