The study found more than 80% of respondents expected their company to increase expenditure in email marketing, with around half saying they would not be re-allocating money from another marketing channel to do so.
The National Client Email Marketing Survey found that 39% of respondents considered direct mail and telemarketing the most successful campaign tools to work alongside email marketing, with 34% putting integrated email and telemarketing in second place.
However, the DMA that said on average companies only had email addresses for 50% of their database.
The DMA study also found email delivery rates were "slightly down" from last year, which it said was due to increased volumes and heightened competition in the sector.
Richard Gibson, chair of the DMA email marketing council's benchmarking hub, said: "It's encouraging to note that many organisations are taking a multi-channel approach to growing their email databases.
"We mustn't underestimate the challenges for many organisations in integrating offline data capture of email addresses -- there needs to be a multi-channel view of the whole customer experience."