public async Task DeleteTemplateAsync(string campaignId, string templateId)
        {
            await _templateRepository.DeleteAsync(campaignId, templateId);

            // reset the whole campaign cache due to weird work of RazorLight built-in cache
            _cache.Remove(CacheKey(campaignId));

            await _log.WriteInfoAsync(nameof(DeleteTemplateAsync), $"Campaign: {campaignId}, TemplateId: {templateId}",
                                      "Email template deleted");
        }