Excellon Resources Inc. announce results from underground drilling at the Platosa Mine in Durango, Mexico. Follow-up drilling on the 817 Zone below Manto 623 defined a zone of high-grade silver mineralization, with underground diamond drilling results including: 2,490 g/t silver equivalent ("AgEq") over 2.9 metres (1,430 g/t Ag, 12.0% Pb, 21.7% Zn) and 5,089 g/t AgEq over 0.4 metres (4,035 g/t Ag, 25.2% Pb, 11.8% Zn) in EX21UG761; 3,905 g/t AgEq over 1.8 metres (2,398 g/t Ag, 14.2% Pb and 33.2% Zn) in EX21UG760; 2,124 g/t AgEq over 2.8 metres (1,267 g/t Ag, 7.5% Pb and 19.0% Zn) in EX21UG812; 4,939 g/t AgEq over 0.9 metres (4,060 g/t Ag, 29.7% Pb, 3.3% Zn) in EX21UG769; 3,158 g/t AgEq over 1.0 metres (2,956 g/t Ag, 6.1% Pb and 1.3% Zn) in EX21UG770. Underground drilling continues to test below historically-mined areas for potential vertical zones.

Follow up drilling on the high-grade interval intersected in EX21UG690 (2,860 g/t AgEq over 7.5 metres) has defined a high-grade, vertical zone on approximately 30 metres of vertical extent. The 817 Zone provides additional dry tonnes to the current mine plan, with production expected to commence from the area as early as February 2022. Drilling from underground continues ahead of production at the NE-1 Manto, and will continue to target areas ahead of production, test the extent of mineralization around mine workings and test for vertical zones of mineralization at the 623, NE-1, Guadalupe Sur, Guadalupe Norte, 4, and 6A/B mantos.

Excellon continues to assess whether maintaining a consistent production schedule at the Platosa Mine is feasible beyond mid-2022 at achievable dewatering rates and with acceptable capital expenditures. The drilling results contained in this news release have been prepared in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101"). Platosa drill core samples are prepared and assayed by SGS Minerals Services in Durango, Mexico.

The lab is accredited to ISO/IEC 17025. Assay turnarounds have been impacted recently by supply and labour shortages related to COVID-19. The Company has a comprehensive QA/QC program, supervised by an independent Qualified Person.

The sampling of, and assay data from, the core sampling and reporting is monitored through a quality assurance and quality control program designed according to best industry practice. Samples from HQ sized drill core are selected by Excellon geologists and cut into halves at the project site. Half of the core is retained at the site for reference purposes.

Sample intervals vary from 0.2 to 1.5 metres in length with samples being selected to honour geological contacts. Samples are labeled and packed into sealed plastic bags which are grouped into larger fiber bags for shipping. A formal chain-of-custody procedure is in place for security of samples from project to laboratory.

Samples are shipped to SGS Laboratories in Durango City. Samples then undergo crushing to two millimetres followed by pulverizing to homogenize samples before a 50-gram sub sample is selected for analysis. The samples are then analyzed using fire assay for gold and silver with a gravimetric finish and multi-element analysis performed by ICP analysis for base metals and multi-element data.