After an international application has been filed other documents may be filed in any proceedings before the EPO direct, by post or - with the exception of authorisations and priority documents - by fax at the EPO filing offices.
OJ 2005, 41, 44
In the case of loss or delay, the EPO accepts evidence of mailing a document only if it was mailed via the postal authorities or if one of the following delivery services was used instead: Chronopost, Deutsche Post Express, DHL, Federal Express, LTA, TNT, SkyNet or UPS.