Under R. 127 EPC, notification may also be effected by means of electronic communication as determined by the President of the EPO and under the conditions laid down by him. However, for this to happen, users must have agreed to receive communications by such means.

R. 127(2) EPC extends to electronic notification the safeguards that already applied for paper. It defines the date on which an electronic document is deemed to be delivered as the tenth day after its transmission. In case of dispute, the Office must prove that the electronic document reached the addressee, or the date on which it reached him. This provision is not limited to any specific technical solution or tool, such as the Mailbox service (see notice of the EPO dated 30 March 2015, OJ 2015, A36).

The President's decision of 11 March 2015 (effective as of 1 April 2015) is currently the legal basis for the EPO's Mailbox service (see notice of the EPO dated 30 March 2015, OJ 2015, A36). It defines the date of transmission, which triggers the ten-day period under R. 127(2) EPC, as the date indicated in the document ("the date of the document"), provided the addressee can access it in the Mailbox by that date. In other words, the ten-day period cannot be considered to have started before the date of the document. If the addressee disputes the date of transmission, it is up to the EPO to establish it. The ten-day period then starts on the date thus established (Art. 9 of the decision, OJ 2015, A28).

Facsimile ("fax") transmission of notifications is generally not admissible (J 27/97) and therefore does not constitute valid notification even if receipt is proven. The situation was different in T 580/06 where notification of a shortfall under point 6.4 ADA was sent only by fax. However, this form of notification was in keeping with point 6.4 ADA in conjunction with R. 77(2)(d) EPC 1973. The President had not laid down conditions for notifications by fax within the meaning of that rule; in particular, postal confirmation of the fax had not been made compulsory. Thus the notification had been made in an appropriate form. In the board's view, the "OK" on the fax transmission report was to be regarded as evidence of complete and error-free transmission, on which the fax became the recipient's responsibility.